Pinealon is a synthetic tripeptide - a chain of just three amino acids (protein building blocks): glutamic acid, aspartic acid, and arginine. It comes from the same Russian research tradition as Epithalon, built on the idea that very short peptides can act as 'bioregulators' that nudge specific genes and protect aging cells. Nearly all of the research on it comes from one group of scientists (led by Vladimir Khavinson) and is published in a narrow set of Russian gerontology journals, usually studying it in aged rats, cells in a dish, or alongside a sister peptide called Vesugen. It is sold as a supplement or 'peptide bioregulator' in some markets, but it is not an approved medicine in the US, EU, or most of the world, and it has never gone through a large, independent clinical trial.
How strong is the evidence?
Of the papers actually about Pinealon in this file, most are rat studies (simulating stroke-like low oxygen, cold stress, or aging) and lab-dish experiments on brain, skin, or pineal gland cells. There are also a handful of small human studies - the largest was a workplace survey of about 300 people (150 truck drivers versus 150 comparison workers), while most others were in the range of roughly 30-110 people, none were randomized or placebo-controlled in the way a modern drug trial would be, and they come from the same research circle. Several other papers in the source file that technically contain the letters 'Glu-Asp-Arg' are actually about unrelated topics (hormone receptor structure, antibody chemistry, crystallin proteins in the eye) and were picked up by a broad search - they were excluded from this analysis. Because there is a real, if thin, thread of human data on top of a fair amount of animal and lab work, this lands as 'limited human evidence,' not full clinical proof and not purely preclinical.
Uses
What people use it for
Brain aging, memory, and mental sharpness
Some human dataThe main reason people look this up: research (mostly in aged rats, plus one small human study) has tested whether it protects brain cells from stress and supports memory and learning as the brain ages.
General anti-aging support ('geroprotector')
Some human dataStudied in older adults with age-related health problems, and in healthy but physically stressed workers, as something that might slow down markers researchers use to estimate 'biological age.'
Stress resilience in demanding jobs
Some human dataTested, combined with the related peptide Vesugen, in truck drivers and train crew workers to see if it could ease work-stress-related anxiety, low mood, and burnout-type symptoms.
Protecting brain cells after low oxygen or blocked blood flow (research setting)
Animal / labA large share of the evidence comes from rat experiments simulating low-oxygen stress, cold stress, and blocked carotid arteries (a stroke-like model) in old animals, not from human injury or stroke studies.
Potential benefits
What it may help with
May help with markers of biological aging
Some human dataIn small human studies, older adults and stressed workers given Pinealon (often alongside Vesugen) showed improvements in the lab and clinical measures researchers use to estimate 'biological age' and overall nervous-system function, compared to their own baseline or to comparison groups.
Eased stress-related mood problems in high-stress jobs
Some human dataIn truck drivers and train crew workers - jobs with irregular schedules and high mental strain - taking Pinealon (combined with Vesugen in most of this work) was linked to better psychological adaptation scores and fewer signs of stress-related mental health strain than before treatment.
Protected brain cells from low oxygen and injury in animal studies
Animal / labIn aged rats, Pinealon eased inflammation-related signals after simulated low-oxygen stress and cold stress, lowered markers of cell death in some models (such as fewer dying neurons in the offspring of stressed pregnant rats), and had the strongest low-oxygen-protective (antihypoxic) effect of several similar peptides tested side by side. The picture is not uniform, though: in the stroke-like blocked-artery model, more animals survived with Pinealon, yet a key cell-death enzyme (caspase-3) actually ticked up slightly rather than down, so 'protection' here means better survival more than a clean drop in cell death.
Supported learning and memory in aging rats
Animal / labOld rats given Pinealon did better navigating a memory maze (the Morris water maze) than untreated old rats, and did somewhat better than rats given a comparison peptide, Cortexin.
Reduced oxidative stress and cell death in lab-grown cells
Animal / labIn cell-dish experiments on brain cells, immune cells (neutrophils), and a nerve-cell line (PC12), Pinealon lowered the buildup of harmful reactive molecules (reactive oxygen species) caused by stress and reduced the number of cells that died. In neurons grown from older donors' skin cells, it also reduced a marker of DNA damage and helped the cells regrow more branches. It is worth noting the picture is not fully consistent: in one lab test the same family of peptides did not act as a direct antioxidant and actually nudged the resting level of reactive molecules upward, even while fewer cells died.
May support skin cell renewal (lab finding only)
Animal / labIn skin tissue taken from young rats and grown in a dish, Pinealon boosted cell proliferation, one early sign researchers look for when exploring whether something might help with skin repair or aging skin. This is a single lab-dish finding, not evidence it visibly improves skin.
Studies:22803085
What to watch for
Side effects & risks
- Moderate
Unexpected sign of extra oxidative stress in one human study
In the one study measuring it directly, researchers found a 'prooxidant' signal (via a chemical test called chemiluminescence) in people taking Pinealon, even though the peptide is generally described as protecting cells from oxidative stress in other experiments. What this means for actual health outcomes wasn't clear from the study.
- Moderate
Drop in a blood stem cell marker (CD34+)
The same human study found a significant decrease in CD34+ cells, a marker of blood-forming stem cells, suggesting the treatment may have held back blood cell production to some degree. The researchers noted the cells didn't appear to be involved in the body's adaptive response, but this is a real signal worth taking seriously, especially for anyone with a blood or bone marrow condition.
- Mild
No effect seen on DNA packaging (a reassuring finding)
The same study checked whether the peptide changed how tightly DNA is packaged in cells (chromatin condensation) and found no effect, which the researchers took as a sign it's safe at the level of the genetic material itself.
- Moderate
It binds directly to DNA and histones - long-term effects untested
Lab studies show Pinealon can get inside a cell's nucleus and physically attach to DNA and the proteins DNA wraps around (histones), in a way that depends on the exact DNA sequence. This is the proposed reason it can turn genes up or down, but there is no long-term human safety data on what repeated exposure to this kind of DNA binding might mean over years.
Dosing
Dosing — what studies used
There is only one place in this research where an exact human dose is spelled out: a two-week study in train crew workers used a 100-microgram capsule of Pinealon, taken by mouth twice a day. Other human studies combined Pinealon with a second peptide, Vesugen, and didn't report an exact dose for Pinealon on its own. The animal studies in this file describe repeated dosing timed around stress events (like low-oxygen exposure or artery blockage), but the abstracts don't give the milligram or microgram amounts used. Outside of that one worker study, there is no well-established, independently confirmed human dose - anyone using it is relying on thin, non-standardized dosing information, often from supplement sellers rather than published trials.
Healthy but physically stressed workers (locomotive crew), aging and adaptation markers
Human trial100 micrograms (mcg) per capsule
1 capsule, twice a day · 2 weeks · Oral capsule
The only study in this file that reports an exact human dose. It measured biological-age and stress-adaptation markers in working adults, not a formal randomized clinical trial.
No study in this file measured how long Pinealon lasts in the human body, and none reported an injectable human dose despite related bioregulator peptides sometimes being given by injection. Treat any other specific dosing schedule you see online as unverified against the research reviewed here.
These figures describe what researchers used in studies. They are not a recommendation or a prescription.
Mechanism
How it works
Pinealon is a very short chain of just three amino acids (the building blocks of protein): glutamic acid, aspartic acid, and arginine. Because it's so small, lab studies show it can slip inside a cell and even into the nucleus, where DNA is stored. Once there, it appears to physically attach to DNA and to the proteins DNA wraps around (called histones), in a way that depends on the exact genetic sequence nearby. Researchers think this lets it turn certain genes up or down, a bit like a dimmer switch for gene activity. In stressed or aging cells, this seems to translate into less buildup of harmful reactive molecules (oxidative stress), fewer cells dying off, and more activity from the body's own antioxidant enzymes. It also appears to affect genes involved in making serotonin (a mood- and brain-signaling chemical) and a hormone called irisin, which is tied to metabolism and aging. All of this is based on animal and lab-dish work; exactly how much of it plays out the same way inside a living human body is still an open question.
Who should avoid it
- Anyone with a blood disorder or bone marrow condition should be cautious, given the one human study that found a drop in a blood stem cell marker (CD34+).
- Not appropriate during pregnancy or breastfeeding in humans - the only pregnancy-related data is in rats, not people, and there's no human safety information for this situation.
- Not appropriate for children - no data exists in this population.
- Anyone considering it should not treat it as a substitute for proven, well-dosed medical care, since it has no approved medical use and no independently confirmed human dosing standard.
Interactions to know
- No human drug interaction studies exist for Pinealon.
- Most human research combined Pinealon with a second peptide, Vesugen, so its effects taken alone versus combined haven't been clearly separated out.
- No data on interactions with blood-thinning, cancer, immune-suppressing, or psychiatric medications, despite its effects on cell growth and blood stem cell markers in the research reviewed.
The papers that matter most
Key studies
The only study in this file with a clear human dose (100 mcg capsule, twice daily, for two weeks); found improvements in biological-age and adaptation markers in train crew workers under occupational stress.
[Analysis of some parameters of biological age and adaptation possibilities of workers of locomotive brigades].
A small study (32 older adults) that found nervous-system and anti-aging benefits from Pinealon and Vesugen, but also flagged a paradoxical prooxidant signal and a drop in a blood stem cell marker (CD34+) - the clearest safety-relevant human data point on file.
[Effect of synthetic peptides on aging of patients with chronic polymorbidity and organic brain syndrome of the central nervous system in remission].
A real-world occupational health study (300 workers) finding that combined Pinealon and Vesugen use was linked to better stress adaptation and fewer stress-related mental health symptoms in high-hazard driving jobs.
[The peptide correction of neurotic disorders among professional truck-drivers].
A foundational mechanism paper showing Pinealon reduces reactive oxygen species and cell death in brain and immune cells in a dish, while also affecting the cell cycle - suggesting it may interact directly with the cell's genetic machinery.
Pinealon increases cell viability by suppression of free radical levels and activating proliferative processes.
Summarizes how Pinealon (EDR) is thought to work at the gene level - binding DNA and histones, affecting stress and antioxidant proteins - and its relevance to Alzheimer's-related brain changes, based on lab and animal data.
EDR Peptide: Possible Mechanism of Gene Expression and Protein Synthesis Regulation Involved in the Pathogenesis of Alzheimer's Disease.
Old and young rats given Pinealon learned a memory maze better than untreated rats, one of the more direct animal demonstrations of a possible memory benefit.
[Effect of peptide geroprotectors on the navigation system learning and caspase-3 in brain structures in rats of different age].
Bottom line
Pinealon has a genuinely interesting research story - reducing cell damage and supporting memory in aged rats, plus a few small human studies suggesting it may ease stress and slow aging markers in older or overworked people. But the human evidence is thin, comes almost entirely from one Russian research group without independent replication, and one of the only detailed human studies also flagged a paradoxical oxidative-stress signal and a drop in a blood stem cell marker. Treat it as a promising but unproven research peptide, not a established anti-aging or brain treatment.
Research papers
Studies we have on file for Pinealon. Tap a title to open it on PubMed. Labels like “animal” or “human trial” are rough guides.
40 papers
Therapeutic Peptides in Orthopaedics: Applications, Challenges, and Future Directions.
Therapeutic peptides are emerging as promising adjuncts in the management of orthopaedic injuries, grounded in their ability to modulate molecular signaling networks central to cellular medicine. By acting on key pathways such as PI3K/Akt, mTOR, MAPK, TGF-β, and AMPK, peptides exert influence over tissue regeneration, inflammation resolution, and neuromuscular recovery. Wound-healing peptides such as BPC-157, TB-500, and GHK-Cu promote angiogenesis, integrin-mediated extracellular matrix remodeling, and fibroblast activation, whereas growth hormone secretagogues like ipamorelin, CJC-1295, tesamorelin, sermorelin, and AOD-9604 activate IGF-1 signaling and satellite cell repair. Recovery-enhancing agents such as epithalon, delta sleep-inducing peptide, and pinealon target circadian and mitochondrial regulators, and neuroactive peptides like selank, semax, and dihexa enhance brain-derived neurotrophic factor and HGF/c-Met pathways critical to neuroplasticity. Although preclinical studies are promising, there is a current lack of clinical trials. This review integrates current mechanistic insights with orthopaedic relevance, emphasizing safety, efficacy, and future directions for responsible integration into musculoskeletal care.
Constitutive activity in gonadotropin receptors.
Constitutively active mutants (CAMs) of gonadotropin receptors are, in general, rare conditions. Luteinizing hormone-choriogonadotropin receptor (LHCGR) CAMs provoke the dramatic phenotype of familial gonadotropin-independent isosexual male-limited precocious puberty, whereas in females, there is not yet any identified phenotype. Only one isolated follicle-stimulating hormone receptor (FSHR) CAM (Asp567Gly) has so far been detected in a single male patient, besides other FSHR weak CAMs linked to pregnancy-associated ovarian hyperstimulation syndrome or to impaired desensitization and internalization. Several animal models have been developed for studying enhanced gonadotropin action; in addition to unraveling valuable new information about the possible phenotypes of isolated FSHR and LHCGR CAMs in women, the information obtained from these mouse models has served multiple translational goals, including the development of new diagnostic and therapeutic targets as well as the prediction of phenotypes for mutations not yet identified in humans. Mutagenesis and computational studies have shed important information on the physiopathogenic mechanisms leading to constitutive activity of gonadotropin receptors; a common feature in these receptor CAMs is the release of stabilizing interhelical interactions between transmembrane domains (TMDs) 3 and 6 leading to an increase, with respect to the wild-type receptor, in the solvent accessibility at the cytosolic extension of TMDs 3, 5, and 6, which involves the highly conserved Glu/Asp-Arg-Tyr/Trp sequence. In this chapter, we summarize the structural features, functional consequences, and mechanisms that lead to constitutive activation of gonadotropin receptor CAMs and provide information on pharmacological approaches that might potentially modulate gonadotropin receptor CAM function.
Synthesis, nano-scale assembly, and in vivo anti-thrombotic activity of novel short peptides containing L-Arg and L-Asp or L-Glu.
Two tripeptides H-Asp(Arg)-Arg (3a) and H-Glu(Arg)-Arg (3b), four pentapeptides H-Asp(Arg-Asp)-Arg-Asp (6a), H-Glu(Arg-Asp)-Arg-Asp (6b), H-Asp(Asp- Arg)-Asp-Arg (10a), and H-Glu(Asp-Arg)-Asp-Arg (10b), and their Cu(II)-peptide complexes Cu(II)-Asp(Arg)-Arg [3a-Cu(II)], Cu(II)-Glu(Arg)-Arg [3b-Cu(II)], Cu(II)-Asp(Arg-Asp)-Arg-Asp [6a-Cu(II)], Cu(II)-Glu(Arg-Asp)-Arg-Asp [6b-Cu(II)], Cu(II)-Asp(Asp-Arg)-Asp-Arg [10a-Cu(II)], and Cu(II)-Glu(Asp-Arg)-Asp-Arg [10b-Cu(II)] were designed and synthesized. Their self-assembling properties and in vivo anti-thrombotic activities were investigated. In normal saline (NS), the Cu(II)-peptide complexes assembled into stable nano-particles surrounded by negative charges (-4.102 to -9.825mV), with diameters ranging from 212.1+/-4.0 to 632.4+/-36.7nm. TEM analysis exhibited that the compounds remained as nano-globes in the solid state, with diameters ranging from 15 to 20nm. In an in vivo anti-thrombotic assay, peptides (3,6,10)a,b at 5micromol/kg reduced the thrombus weights of a rat model by 15-40%. Aspirin, a widely used anti-thrombotic drug, achieved comparable activity in this model system at a dosage of ca. 110micromol/kg. The required dosage of Cu(II)-peptide complexes [(3,6,10)a,b]-Cu(II), which assemble into stable nano-particles, was significantly reduced to 0.05micromol/kg. Therefore, the anti-thrombotic activity of the nano-particles [(3,6,10)a,b]-Cu(II) increased dramatically by 100-fold over that of the corresponding peptides.
Pinealon protects the rat offspring from prenatal hyperhomocysteinemia.
The offspring of rats with experimental hyperhomocysteinemia caused by alimentary loading with dietary methionine within pregnancy has been studied. Using pinealon (Glu-Asp-Arg) under these conditions was found to result in the offspring cognitive function being improved significantly and their cerebellum neurons becoming more resistant to oxidative stress. This may be proved by the fact that the administration of pinealon to pregnant rats loaded with methionine improved their offspring spatial orientation and learning ability and decreased both reactive oxygen species accumulation and the number of necrotic cells in the population of the neurons isolated from the cerebellum of the offspring developed under the prenatal hyperhomocysteinemia. Our experiments allowed confirming the neuroprotective properties of pinealon, which is in agreement with the previous data obtained by us in vitro.
[EFFECT OF SYNTHETIC PEPTIDES ON AGING OF PATIENTS WITH CHRONIC POLYMORBIDITY AND ORGANIC BRAIN SYNDROME OF THE CENTRAL NERVOUS SYSTEM IN REMISSION].
We've estimated the cellular and metabolic part of geroprophylactic effects of short synthetic tripeptides vesugen and pinealon for correction of the biological age. 32 people (18 men, 12 women) aged 41-83 years with polymorbidity and the organic brain syndrome in remission participated in the study. The preparations of "Pinealon" and "Vesugen" have had the significant anabolic effect. They have improved the activity of the Central nervous system and other vital organs, which slows the rate of aging by biological age indicators. Vesugen has demonstrated more visible geroprophylactic effect than Pinealon. At the same time we've found the prooxidant activity through chemiluminescence. Decrease of markers CD34+ positive hematopoietic polypotent cells in blood has shown significant inhibition of hemopoiesis. Apparently, the cells have not been involved in the adaptive reactions. Pinealon and Vesugen haven't affected the degree of chromatin condensation, so they are safe on nuclear genetic level. This property should be studied in future. In geriatric practice, we recommend to apply the peptides Pinealon and Vesugen as geroprotectors anabolic neuroprotective and no antioxidant type for reducing the rate of aging in patients with the organic brain syndrome vascular and/or traumatic genesis.
Pinealon increases cell viability by suppression of free radical levels and activating proliferative processes.
The synthetic tripeptide pinealon (Glu-Asp-Arg) demonstrates dose-dependent restriction of reactive oxygen species (ROS) accumulation in cerebellar granule cells, neutrophils, and pheochromocytoma (PC12) cells, induced by oxidative stress stimulated by receptor-dependent or -independent processes. At the same time, pinealon decreases necrotic cell death measured by the propidium iodide test. The protective effect of pinealon is accompanied with a delayed time course of ERK 1/2 activation and modification of the cell cycle. Because restriction of ROS accumulation and cell mortality is saturated at lower concentrations, whereas cell cycle modulation continues at higher concentrations of pinealon, one can conclude that besides its known antioxidant activity, pinealon is able to interact directly with the cell genome.
Effect of seabuckthorn seed protein and its arginine-enriched peptides on combating memory impairment in mice.
The current study characterized the combating memory impairment effect of seabuckthorn seed protein (SSP) and the arginine (Arg)-enriched peptides (SSPP) on d-galactose-induced brain aging in mice. The Arg content in SSP and SSPP were 10.11 and 17.82 g/100 g, respectively. Seven Arg peptides (Ile/Leu-Arg, Arg-Glu, Asp-Arg-Pro, Arg-Try-Ala, Glu-Arg-Ser, Val-Gly-Arg-Pro, and Lys-Thr-Glu-Arg) were identified from SSPP. The animal experiments of the Morris water maze and the step-down test indicated that the oral administration of SSP (0.25, 0.5, 1.0 mg/g·d) and SSPP (0.25, 0.5, 1.0 mg/g·d) significantly (p < 0.05) reversed the learning and memory impairment symptoms. The activation of endothelial nitric oxide (NO) synthase and neuronal NO synthase were increased, and inducible NO synthase decreased after SSP and SSPP in the hippocampus compared to the model group, with the SSPP being quite effective. Moreover, the treatment significantly exhibited the ability to normalize the serum inflammatory cytokine levels (NF-ĸB, TNF-α, IL-6) and suppress the Arg-inducible nitric oxide (Arg-iNO) pathway. Therefore, SSP and SSPP ingestion reversed the behavioral learning and memory impairment symptoms possibly associated with the anti-inflammation and Arg-iNO pathway. Consumption of SSP and SSPP diets can be beneficial to memory impairment.
The Role of Amino Acids in the Diagnosis, Risk Assessment, and Treatment of Breast Cancer: A Review.
This review summarizes the role of amino acids in the diagnosis, risk assessment, imaging, and treatment of breast cancer. It was shown that the content of individual amino acids changes in breast cancer by an average of 10-15% compared with healthy controls. For some amino acids (Thr, Arg, Met, and Ser), an increase in concentration is more often observed in breast cancer, and for others, a decrease is observed (Asp, Pro, Trp, and His). The accuracy of diagnostics using individual amino acids is low and increases when a number of amino acids are combined with each other or with other metabolites. Gln/Glu, Asp, Arg, Leu/Ile, Lys, and Orn have the greatest significance in assessing the risk of breast cancer. The variability in the amino acid composition of biological fluids was shown to depend on the breast cancer phenotype, as well as the age, race, and menopausal status of patients. In general, the analysis of changes in the amino acid metabolism in breast cancer is a promising strategy not only for diagnosis, but also for developing new therapeutic agents, monitoring the treatment process, correcting complications after treatment, and evaluating survival rates.
Penetration of short fluorescence-labeled peptides into the nucleus in HeLa cells and in vitro specific interaction of the peptides with deoxyribooligonucleotides and DNA.
Marked fluorescence in cytoplasm, nucleus, and nucleolus was observed in HeLa cells after incubation with each of several fluorescein isothiocyanate-labeled peptides (epithalon, Ala-Glu-Asp-Gly; pinealon, Glu-Asp-Arg; testagen, Lys-Glu-Asp-Gly). This means that short biologically active peptides are able to penetrate into an animal cell and its nucleus and, in principle they may interact with various components of cytoplasm and nucleus including DNA and RNA. It was established that various initial (intact) peptides differently affect the fluorescence of the 5,6-carboxyfluorescein-labeled deoxyribooligonucleotides and DNA-ethidium bromide complexes. The Stern-Volmer constants characterizing the degree of fluorescence quenching of various single- and double-stranded fluorescence-labeled deoxyribooligonucleotides with short peptides used were different depending on the peptide primary structures. This indicates the specific interaction between short biologically active peptides and nucleic acid structures. On binding to them, the peptides discriminate between different nucleotide sequences and recognize even their cytosine methylation status. Judging from corresponding constants of the fluorescence quenching, the epithalon, pinealon, and bronchogen (Ala-Glu-Asp-Leu) bind preferentially with deoxyribooligonucleotides containing CNG sequence (CNG sites are targets for cytosine DNA methylation in eukaryotes). Epithalon, testagen, and pinealon seem to preferentially bind with CAG- but bronchogen with CTG-containing sequences. The site-specific interactions of peptides with DNA can control epigenetically the cell genetic functions, and they seem to play an important role in regulation of gene activity even at the earliest stages of life origin and in evolution.
Role of Mono- and Divalent Ions in Peptide Glu-Asp-Arg-DNA Interaction.
The interaction of the regulatory biologically active peptide Glu-Asp-Arg (EDR) with DNA is considered by spectral, NMR, viscosimetry, and molecular dynamics methods. It was shown that EDR can partly penetrate into the major groove of DNA and affect the base atoms, mainly the N7 and O6 of guanine. It was observed that Mg2+ ions can promote DNA-EDR interaction due to their effective screening of the negatively charged phosphate groups of DNA. This action of Mg2+ remains in salted solution as well.
[Regulation of content of cytokines in blood serum and of caspase-3 activity in brains of old rats in model of sharp hypoxic hypoxia with Cortexin and Pinealon].
While studying the effects of Cortexin and Pinealon (Glu-Asp-Arg) on the caspase-3 activity in the brain, an interleykin-6 and a factor of tumor necrosis in blood serum of old rats under the sharp hypoxic hypoxia it was suggested that in hypoxia of brain conditions Pinealon forwards the increase of the neurogenesis and the decrease neuroinflammatory reactions to a reference level. With the sharp hypoxic hypoxia Cortexin reduces an ability of brain tissue of programmed cells death, but saves the content of interleykin-6 at high level.
[Comparative analysis of different methods of geroprotective].
In the monitoring process 110 representatives of different age groups held a comparative analysis of the efficacy and safety of several geroprotective techniques, including the use of dry carbon dioxide baths, hyperbaric oxygen therapy, therapeutic massage and receiving Oligopeptide preparations containing complexes lysyl-glutamyl-asparagin and glutamyl-asparagin-arginine (Vezugen and Pinealon). The most pronounced positive impact on indicators of biological age were detected during the combined use of these two Oligopeptide complexes. The most safe from the point of view of influence on a number of biochemical, immunological parameters, clinical condition of the patients were therapeutic massage and Oligopeptide drugs. The use of dry carbon dioxide baths and hyperbaric oxygenation with an undoubtedly positive influence on the indices of biological age has a number of limitations and contraindications regarding its security.
Short Peptides Protect Fibroblast-Derived Induced Neurons from Age-Related Changes.
Neurons become more vulnerable to stress factors with age, which leads to increased oxidative DNA damage, decreased activity of mitochondria and lysosomes, increased levels of p16, decreased LaminB1 proteins, and the depletion of the dendritic tree. These changes are exacerbated in vulnerable neuronal populations during the development of neurodegenerative diseases. Glu-Asp-Arg (EDR) and Lys-Glu-Asp (KED), and Ala-Glu-Asp-Gly (AEDG) peptides have previously demonstrated neuroprotective effects in various models of Alzheimer's disease. In this study, we investigated the influence of EDR, KED, and AEDG peptides on the aging of fibroblast-derived induced neurons. We used a new in vitro cellular model of human neuronal aging based on the transdifferentiation of aged dermal fibroblasts from elderly donors into induced cortical neurons. All peptides promote the arborization of the dendritic tree, increasing both the number of primary processes and the total length of dendrites. Tripeptides have no effect on the activity of mitochondria and lysosomes and the level of p16 protein in induced neurons. EDR peptide reduces oxidative DNA damage in induced neurons derived from elderly donor fibroblasts. Short peptides partially protect induced neurons from age-related changes and stimulate dendritogenesis in neurons. They can be recommended for use as neuroprotective agents.
Short Peptides and Telomere Length Regulator Hormone Irisin.
Irisin produced by muscles during exercise and promoting fat burning also exhibits geroprotective effect and induces telomere elongation in normal somatic cells. Special attention is paid to studies of the role of peptides Lys-Glu, Glu-Asp-Arg, and Ala-Glu-Asp-Gly in epigenetic regulation of irisin content. The data suggest that the immunomodulatory peptide Lys-Glu and neuroprotective peptide Glu-Asp-Arg modulate the life span by modulating irisin gene expression.
EDR Peptide: Possible Mechanism of Gene Expression and Protein Synthesis Regulation Involved in the Pathogenesis of Alzheimer's Disease.
The EDR peptide (Glu-Asp-Arg) has been previously established to possess neuroprotective properties. It activates gene expression and synthesis of proteins, involved in maintaining the neuronal functional activity, and reduces the intensity of their apoptosis in in vitro and in vivo studies. The EDR peptide interferes with the elimination of dendritic spines in neuronal cultures obtained from mice with Alzheimer's (AD) and Huntington's diseases. The tripeptide promotes the activation of the antioxidant enzyme synthesis in the culture of cerebellum neurons in rats. The EDR peptide normalizes behavioral responses in animal studies and improves memory issues in elderly patients. The purpose of this review is to analyze the molecular and genetics aspects of the EDR peptide effect on gene expression and synthesis of proteins involved in the pathogenesis of AD. The EDR peptide is assumed to enter cells and bind to histone proteins and/or ribonucleic acids. Thus, the EDR peptide can change the activity of the MAPK/ERK signaling pathway, the synthesis of proapoptotic proteins (caspase-3, p53), proteins of the antioxidant system (SOD2, GPX1), transcription factors PPARA, PPARG, serotonin, calmodulin. The abovementioned signaling pathway and proteins are the components of pathogenesis in AD. The EDR peptide can be AD.
[Neuroprotective effects of peptides bioregulators in people of various age].
The review presents comparative characteristics of 2 peptide neuroprotective groups: polypeptide complexes (cortexin, cerebrolizin) and short peptides (semax, kortagen, pinealon). The data of clinical applying of peptides in elderly and old age people and cellular and molecular mechanisms of their neuroprotective activity is described.
[Analysis of some parameters of biological age and adaptation possibilities of workers of locomotive brigades].
The unfavorable factors of professional work of workers of locomotive brigades influence on speed of aging and adaptation possibilities of an organism. Analysis of the data obtained confirms the positive use of the peptide bioregulator Pinealon in maintenance the professional reliability of workers of locomotive brigades. Workers of locomotive brigades used preparation during two weeks (1 capsule containing 100 mkg of Pinealon 2 times a day). Pinealon application has improved parameters of biological age and indicators determining the effectiveness of adaptive reactions.
[Investigation of antihypoxic properties of short peptides].
The data presented suggest that short regulatory peptides (vilon, epitalon, vesugen and pinealon) have manifested the antihypoxic properties in the model of hypobaric hypoxia. Pinealon (Glu-Asp-Arg) has the most pronounced effect among them. The capability of pinealon to increase the neuronal resistance to hypoxic stress in experiments with prenatal hypoxia has a complex nature. It is based not so much on the inhibition of ROS increase in cells in response to stress as on stimulation of internal antioxidative enzyme system and possibly limiting the excitotoxic effect of N-methyl-D-aspartate.
[Prospects for use of short peptides in pharmacotherapeutic correction of Alzheimer's disease.].
Alzheimer's disease (AD) is the most common neurodegenerative disorder, characterized by progressive cognitive decline. This review discusses current therapeutic strategies for the treatment of Alzheimer's disease, their limitations, and potential prospects. The feasibility of comprehensive approach for AD therapy is considered in contrast to the classical method in the development of therapeutic strategy. Leu-Ile, Glu-Trp, Lys-Glu, Gly-Pro, Glu-Asp-Arg, Lys-Glu-Asp, Met-Glu-His-Phe-Pro-Gly-Pro short peptides are described as multitarget agents with a wide range of activity.
[Pinealon and Cortexin influence on behavior and neurochemical processes in 18-month aged rats within hypoxia and hypothermia].
The research of Cortexin and Pinealon within two models of stress, acute hypobaric hypoxia and mild hypothermia, within 18-month aged rats has been held. The peculiarities of peptide preparations' influence on behavior and neurochemical indeces have been identified. Cortexin shows a more pronounced effect on free radical processes and caspase 3 activity in brain than Pinealon. Both preparations forward an accumulation of adrenergic mediator within rats' brains in the model of acute hypobaric hypoxia, as well as serotonin within cerebrum cortex in the model of mild hypothermia, which may underlie their geroprotective effects.
Tetrapeptide H-Ala-Glu-Asp-Arg-OH stimulates expression of cytoskeletal and nuclear matrix proteins.
Tetrapeptide H-Ala-Glu-Asp-Arg-OH enhances the expression of cytoskeletal (actin, tubulin, vimentin) and nuclear matrix proteins (lamin A, lamin C) in cultured mouse embryonic fibroblasts by 2-5 and 2-3 times, respectively. Thus, the previously reported cardioprotective activity of this tetrapeptide is determined by its capacity to activate synthesis of cytoskeletal and nuclear matrix proteins, which stimulates cell proliferation and reduces apoptosis.
Angiotensin II restricted analogs with biological activity in the erythrocytic cycle of Plasmodium falciparum.
The anti-plasmodial activity of conformationally restricted analogs of angiotensin II against Plasmodium gallinaceum has been described. To observe activity against another Plasmodium species, invasion of red blood cells by Plasmodium falciparum was analyzed. Analogs restricted with lactam or disulfide bridges were synthesized to determine their effects and constraints in the peptide-parasite interaction. The analogs were synthesized using tert-butoxycarbonyl and fluoromethoxycarbonyl solid phase methods, purified by liquid chromatography, and characterized by mass spectrometry. Results indicated that the lactam bridge restricted analogs 1 (Glu-Asp-Arg-Orn-Val-Tyr-Ile-His-Pro-Phe) and 3 (Asp-Glu-Arg-Val-Orn-Tyr-Ile-His-Pro-Phe) showed activity toward inhibition of ring formation stage of P. falciparum erythrocytic cycle, preventing invasion in about 40% of the erythrocytes. The disulfide-bridged analog 10 (Cys-Asp-Arg-Cys-Val-Tyr-Ile-His-Pro-Phe) was less effective yet significant, showing a 25% decrease in infection of new erythrocytes. In all cases, the peptides presented no pressor activity, and hydrophobic interactions between the aromatic and alkyl amino acid side chains were preserved, a factor proven important in efficacy against P. gallinaceum. In contrast, hydrophilic interactions between the Asp(1) carboxyl and Arg(2) guanidyl groups proved not to be as important as they were in the case of P. gallinaceum, while interactions between the Arg(2) guanidyl and Tyr(4) hydroxyl groups were not important in either case. The β-turn conformation was predominant in all of the active peptides, proving importance in anti-plasmodial activity. This approach provides insight for understanding the importance of each amino acid residue on the native angiotensin II structure and a new direction for the design of potential chemotherapeutic agents.
[The peptide correction of neurotic disorders among professional truck-drivers].
This study was designed to estimate the neurobehavioral status and to compare the prevalence of psychoadaptive disorders among lorry-drivers (experimental group) and metal craftsmen (control group) in connection with their age, length of service, occupational hazards, work schedule and sociodemographic characteristics. 150 male lorry-drivers (mean age 43.3 +/- 0.9) and 150 male metal craftsmen (mean age 42.8 +/- 0.9) were examined using a clinical questionnaire to identify, estimate and compare neurotic states. The study comprised 3 groups: 1st--subjects with stable psychic adaptation, 2nd--subjects with unstable psychic adaptation, a risk group, 3rd--subjects with stable psychic disadaptation, i.e. with some borderline mental disorders (BMD). Significant differences in the prevalence of psychic adaptation and disadaptation among groups under study were found. The predominance of the 2nd and 3rd groups among lorry-drivers in comparison with control group was found. The results showed that social and demographic characteristics had no significant influence neither in experimental nor in control groups (p > 0.1). Variability of psychoemotional imbalance levels among lorry-drivers was found to be due to a combination of the following factors: occupational exposure and their work schedule, while in control group--to the age of metal craftsmen. Comparative analysis of neurobehavioral disorders revealed the predominance of the asthenic symptoms, anxious and depressive manifestations, hysterical reactions among lorry-drivers, and the vegetative disorders only in control group. The results thus obtained support the hypothesis of occupational hazards and long driving experience being the risk factors for the development of BMD. The application of bioregulating peptides was found to restore the organism adaptive potential, improved psychoemotional indices, intensified resistance to work stress and reduced occupational risk of borderline mental disorders (p < 0.001-0.05). The best effect was obtained in case of combined application of several cytogens (pinealon and vezugen), which were optimally selected regarding the effect of each adverse occupational factor on a target organ or system. The employed parameters of psychoemotional state were rather informative for assessing the peptidergic properties of cytogens in occupational medicine and geriatrics.
[Effects of introduction of short peptides before carotid artery occlusion on behaviour and caspase-3 activity in the brain of old rats].
The comparative research of effect of Pinealon and Cortexin on behavior and activity of caspase-3 in a brain of old rats in a model of carotid arteries occlusion was conducted. It is shown that introduction of short peptides promotes a survival rate of the animals that have modeled occlusion of carotid arteries. Under Pinealon before occlusion of carotid arteries, behavioral dream has been increased and a position-finding behavior, a motivational behavior and a motor performance have been reduced. The rats that were introduced Cortexin before carotid arteries occlusion demonstrated the raise of behavioral dream time. At introduction of Pinealon activity of caspase-3 moderately raises in false-operated animals and in a model of occlusion of carotid arteries.
Effect of short peptides on expression of signaling molecules in organotypic pineal cell culture.
We demonstrated the influence of short peptides on the expression of signaling molecules in organotypic culture of the pineal gland from 3-month-old rats. Peptides Ala-Glu-Asp-Gly and Lys-Glu-Asp stimulate the expression of proliferative protein Ki-67 in pineal gland culture. These peptides as well as Glu-Asp-Arg and Lys-Glu do not affect the expression of apoptosis marker AIF. The synthesis of transcription factor CGRP by pinealocytes was stimulated only by Ala-Glu-Asp-Gly. Thus, peptide Ala-Glu-Asp-Gly tissue-specifically stimulates proliferative and secretory activities of pinealocytes, which can be used for recovery of pineal gland functions at the molecular level.
Short peptides stimulate serotonin expression in cells of brain cortex.
Peptides Glu-Asp-Arg and Lys-Glu-Asp stimulate serotonin expression in aging cultures of brain cortex cells. Peptide regulation of 5-tryptophan hydroxylase gene encoding the enzyme involved in serotonin synthesis was demonstrated by the molecular docking method. The CCTGCC nucleotide sequence in 5-tryptophan hydroxylase gene was found to be complementary to these peptides. Hence, Glu-Asp-Arg and Lys-Glu-Asp peptides epigenetically regulate serotonin synthesis in the brain cortex, which indicates their neuro- and geroprotective activities.
Effect of bioregulatory tripeptides on the culture of skin cells from young and old rats.
We studied the effects of synthesized tripeptides T-32 (Glu-Asp-Ala), T-33 (Glu-Asp-Arg), T-34 (Glu-Asp-Gly), T-36 (Glu-Asp-Pro), and T-38 (Lys-Glu-Asp) on organotypic skin cultures of young and old rats. In skin explants from young rats, all peptides except T-34 produced a stimulating effect on cell proliferation. In skin explants from old rats, tripeptide T-38 produced a marked stimulatory effect on proliferation. Immunocytochemical study of the proapoptotic p53 protein expression showed that cell proliferation increased due to less pronounced apoptosis. The capacity of the studied tripeptides to promote cell proliferation in the skin tissues of young and old animals provides the basis for further study of these substances as preparations boosting the regenerative processes in the skin, including those at age-associated pathology.
Mutational analysis of the highly conserved arginine within the Glu/Asp-Arg-Tyr motif of the alpha(1b)-adrenergic receptor: effects on receptor isomerization and activation.
We have suggested previously that both the negatively and positively charged residues of the highly conserved Glu/Asp-Arg-Tyr (E/DRY) motif play an important role in the activation process of the alpha(1b)-adreneric receptor (AR). In this study, R143 of the E/DRY sequence in the alpha(1b)-AR was mutated into several amino acids (Lys, His, Glu, Asp, Ala, Asn, and Ile). The charge-conserving mutation of R143 into lysine not only preserved the maximal agonist-induced response of the alpha(1b)-AR, but it also conferred high degree of constitutive activity to the receptor. Both basal and agonist-induced phosphorylation levels were significantly increased for the R143K mutant compared with those of the wild-type receptor. Other substitutions of R143 resulted in receptor mutants with either a small increase in constitutive activity (R143H and R143D), impairment (R143H, R143D), or complete loss of receptor-mediated response (R143E, R143A, R143N, R143I). The R413E mutant displayed a small, but significant increase in basal phosphorylation despite being severely impaired in receptor-mediated response. Interestingly, all the arginine mutants displayed increased affinity for agonist binding compared with the wild-type alpha(1b)-AR. A correlation was found between the extent of the affinity shift and the intrinsic activity of the agonists. The analysis of the receptor mutants using the allosteric ternary complex model in conjunction with the results of molecular dynamics simulations on the receptor models support the hypothesis that mutations of R143 can drive the isomerization of the alpha(1b)-AR into different states, highlighting the crucial role of this residue in the activation process of the receptor.
[Effect of peptide geroprotectors on the navigation system learning and caspase-3 in brain structures in rats of different age].
The study of the effects of peptide geroprotectors cortexin and pinealon on the system of caspase-3 in the brain structures and training of rats of different ages was held. Regional changes in activity and the content of caspase-3 in the cerebral cortex and brainstem of young and old rats under the influence of peptides were identified. It is suggested that the functional state of caspase-3 in the brain is one of the reasons that determines the animals' ability to learn. Pinealon has prevalent positive effect on learning of both young and old animals in the Morris labyrinth compared to cortexin.
Radiolabelling of lipid-based nanocarriers with fluorine-18 for in vivo tracking by PET.
Organic nanoparticles made out of biodegradable and biocompatible materials have attracted increased attention in the therapeutic and diagnostic fields. In this study, we attempted to explore a new radiolabelling chelating free strategy for biodegradable sphingomyelin nanometric emulsions with fluorine-18 (18F), a radioisotope regularly used in clinic. [18F]fluoride was produced by the cyclotron and was incorporated into 4-[18F]fluorobenzamido-N-ethylmaleimide ([18F]FBEM), which was coupled next to the emulsions previously functionalized with a thiol group, via inclusion of either a thiol-PEG-lipid (SH-PEG12-C18), or a peptide-PEG-lipid (Cys-Pro-Ile-Glu-Asp-Arg-Pro-Met-Cys-PEG8-C18) derivative. Radiolabelled emulsions were obtained in a rapid and efficient fashion through facile-conjugated chemistry without the use of organic solvents, and characterized in terms of size, polydispersity, surface charge, pH, and osmolarity. PET imaging and biodistribution studies in BALB/c mice allowed obtaining the pharmacokinetics of the radiolabelled emulsions and determining the clearance pathways. Altogether, we confirmed the potential of this new technique for the radiolabelling of lipid-based drug nanosystems for application in PET imaging diagnosis.
Interaction of short peptides with FITC-labeled wheat histones and their complexes with deoxyribooligonucleotides.
Judging from fluorescence modulation (quenching), short peptides (Ala-Glu-Asp-Gly, Glu-Asp-Arg, Ala-Glu-Asp-Leu, Lys-Glu-Asp-Gly, Ala-Glu-Asp-Arg, and Lys-Glu-Asp-Trp) bind with FITC-labeled wheat histones H1, H2B, H3, and H4. This results from the interaction of the peptides with the N-terminal histone regions that contain respective and seemingly homologous peptide-binding motifs. Because homologous amino acid sequences in wheat core histones were not found, the peptides seem to bind with some core histone regions having specific conformational structure. Peptide binding with histones and histone-deoxyribooligonucleotide complexes depends on the nature of the histone and the primary structures of the peptides and oligonucleotides; thus, it is site specific. Histones H1 bind preferentially with single-stranded oligonucleotides by homologous sites in the C-terminal region of the protein. Unlike histone H1, the core histones bind predominantly with double-stranded methylated oligonucleotides and methylated DNA. Stern-Volmer constants of interaction of histone H1 and core histones with double-stranded hemimethylated oligonucleotides are higher compared with that of binding with unmethylated ones. DNA or deoxyribooligonucleotides in a complex with histones can enhance or inhibit peptide binding. It is suggested that site-specific interactions of short biologically active peptides with histone tails can serve in chromatin as control epigenetic mechanisms of regulation of gene activity and cellular differentiation.
Structure and function in rhodopsin: rhodopsin mutants with a neutral amino acid at E134 have a partially activated conformation in the dark state.
The Glu-134-Arg-135 residues in rhodopsin, located near the cytoplasmic end of the C helix, are involved in G protein binding, or activation, or both. Furthermore, the charge-neutralizing mutation Glu-134 to Gln-134 produces hyperactivity in the activated state and produces constitutive activity in opsin. The Glu/Asp-Arg charge pair is highly conserved in equivalent positions in other G protein-coupled receptors. To investigate the structural consequences of charge-neutralizing mutations at Glu-134 and Arg-135 in rhodopsin, single spin-labeled side chains were introduced at sites in the cytoplasmic domains of helices C (140), E (227), F (250), or G (316) to serve as "molecular sensors" of the local helix bundle conformation. In each of the spin-labeled rhodopsins, a Gln substitution was introduced at either Glu-134 or Arg-135, and the electron paramagnetic resonance spectrum of the spin label was used to monitor the structural response of the helix bundle. The results indicate that a Gln substitution at Glu-134 induces a photoactivated conformation around helices C and G even in the dark state, an observation of potential relevance to the hyperactivity and constitutive activity of the mutant. In contrast, little change is induced in helix F, which has been shown to undergo a dominant motion upon photoactivation. This result implies that the multiple helix motions accompanying photoactivation are not strongly coupled and can be induced to take place independently. Gln substitution at Arg-135 produces only minor structural changes in the dark- or light-activated conformation, suggesting that this residue is not a determinant of structure in the regions investigated, although it may be functionally important.
Subsite preferences of pepstatin-insensitive carboxyl proteinases from bacteria.
Pseudomonas sp. 101 carboxyl proteinase (PCP) and Xanthomonas sp. T-22 carboxyl proteinase (XCP), the first and second unique carboxyl proteinases from prokaryotes to be isolated and characterized, are not inhibited by the classical carboxyl proteinase inhibitor pepstatin. In this study, we elucidated their subsite preferences by using a series of synthetic chromogenic substrates, Lys-Pro-Ile(P3)-Glu(P2)-Phe*Nph-Arg(P2')-Leu(P3') (Nph is p-nitrophenylalanine, Phe*Nph is the cleavage site) with systematic substitutions at the P3, P2, P2', and P3' positions. Among 45 substrates tested, the best substrate for PCP had a Leu replacement at the P2 position (kcat = 27.2 s-1, Km = 4.22 microM, kcat/Km = 6.43 microM-1.s-1), and that for XCP had an Ala replacement at the P3 position (kcat = 79.4 s-1, Km = 6.05 microM, kcat/Km = 13.1 microM-1. s-1). PCP and XCP preferred such charged amino acid residues as Glu, Asp, Arg, or Lys at the P2' position. This suggested that the S2' subsites of PCP and XCP are occupied by hydrophilic residues, similar to that of pepstatin-insensitive carboxyl proteinase from Bacillus coagulans J-4 [Shibata et al. (1998) J. Biochem. 124, 642-647]. In contrast, the S2' subsite of pepstatin-sensitive carboxyl proteinases (aspartic proteinases) is hydrophobic in nature. Thus, the hydophilic nature of the S2' subsite appears to be a distinguishing feature of pepstatin-insensitive carboxyl proteinases.
Gamma III-crystallin is the primary target of glycation in the bovine lens incubated under physiological conditions.
Several mechanisms have been proposed for the way in which glucose and its metabolites cause cataract, retinopathy and other complications of diabetes, the most convincing being glycation. Glycation, the reaction of sugars with free amino groups of proteins, is one of a variety of non-enzymic post-translational modifications. The aim of the present study was to identify some of the most reactive proteins in the lens when incubated under physiological conditions. Fresh intact bovine lenses were incubated with [14C]glucose in a conventional tissue-culture medium with added antibiotics. After 3 and 6 days of incubation, the water-soluble proteins were separated by size-exclusion chromatography. Glycated proteins from the water-soluble fractions were separated by using a sugar affinity column (Affi-Gel 601). Then the radioactive fractions were identified on SDS/polyacrylamide gels. In addition, the whole bovine lenses were incubated with 10 mM fructose and glucose for 3 and 6 days. The glycated proteins from the water-soluble fractions in parallel with the radioactive fractions were separated by affinity chromatography, and were identified further by amino-acid sequencing. A progressive uptake of radioactive label showed that the majority of proteins incorporating both glucose and fructose were water-soluble fractions. Chromatography and SDS/polyacrylamide gel results showed that alpha- and gamma-crystallin and some proteins of a mean molecular mass of 36-37 kDa incorporated sugars early during incubation. After 6 days of incubation, more crystallins were glycated compared with 3 days, in particular beta-crystallin. Affinity-chromatography results indicated that proteins with subunit masses of 36 kDa and 20 kDa were possibly radiolabelled at an early stage. The purified glycated proteins following incubation with both glucose and fructose, which corresponded to 20 kDa and 36 kDa bands on SDS/polyacrylamide gels, were sequenced by Edman degradation. N-terminal sequences of both 20 kDa bands were Gly-Lys-Ile-Thr, characteristic of gamma-crystallins, but the N-termini of both 36 kDa bands were blocked. Further sequencing after digestion of 36 kDa bands with trypsin and running on HPLC revealed that the glucose sample gave the peptide sequences as Gly-Glu-Tyr-Pro-Asp-Tyr-Gln-Gln and Tyr-Glu-Leu-Pro-Asn-Tyr-Arg, which match with bovine gammaIIIb-crystallin. The peptide sequence Tyr-Glu-Leu-Pro-Asn-Tyr-Arg is only present in the published sequence of bovine gammaIIIb-crystallin and not in any other type of gamma-crystallin. The fructose sample gave the peptide sequences Ile-Thr-Phe-Tyr-Glu-Asp-Arg, Arg-Gly-Asp-Tyr-Pro-Asp-Tyr-Gln-Gln-Trp, Gln-Tyr-Leu-Leu-Arg and Val-Val-Asp-Leu-Tyr, which all matched with bovine gammaIIIa-crystallin. The sequence Val-Val-Asp-Leu-Tyr only appears in the sequence of bovine gammaIIIa-crystallin. gammaIII-Crystallin is the most susceptible lens protein to glycation. The primary target of glucose is gammaIIIb-crystallin, whereas that of fructose is gammaIIIa-crystallin. The early glycation of gammaIII-crystallin by glucose and fructose could result in structural alterations, leading to aggregation of crystallin and eventually cataract formation.
Curious structure in "canonical" alanine-based peptides.
We have performed all atom simulations of blocked peptides of the form (AAXAA)3, where X = Gln, Asn, Glu, Asp, Arg, and Lys with explicit water molecules to examine the interactions between side chains spaced i,i-5 in the sequence. Although side chains in this i,i-5 arrangement are commonly believed to be noninteracting, we have observed the formation of unusual i,i-5 main chain hydrogen bonding in such sequences with positively charged residues (Lys) as well as polar uncharged groups (Gln). Our results are consistent with the unusual percentage of hydrogen bonding curves produced by amide exchange measurements on the well-studied sequence acetyl-(AAQAA)3-amide in water (Shalongo, W., Dugad, L., Stellwagen, E. J. Am. Chem. Soc. 116:8288-8293, 1994). Analysis of our simulations indicated that the glutamine side chain showed the greatest propensity to support pi helix formation and that the i,i-5 intramolecular hydrogen bonds were stabilized by water-bridging side chain interactions. This intermittent formation of the unusual pi helix structure was observed for up to 23% of the total simulation time in some residues in (AAQAA)3. Control studies on peptides with glutamine side chains spaced i,i-3, i,i-4 and i,i-6 did not reveal similar unique structures, providing stronger evidence for the unique role side chain interactions with i,i-5 spacing.
[Biological activity of regulatory peptides in model experiments in vitro].
Biological effects of short regulatory peptides, pinealon, vesugen, vilon and epitalon were studied in model experiments in vitro. These peptides were found not to demonstrate direct antioxidant activity but be able to restrict lipid peroxidation of human lipoproteins by modification of their structure. The short peptides increase stability of red blood cell membranes toward osmotic hemolysis. They also elevate the stationary level of intracellular reactive oxygen species and at the same time decrease (all excepting epitalon) percent of dead cells in neuronal population. The suggestion was made that under in vivo conditions, short peptides may participate in apoptosis/necrosis regulation.
Antigen-antibody interface properties: composition, residue interactions, and features of 53 non-redundant structures.
The structures of protein antigen-antibody (Ag-Ab) interfaces contain information about how Ab recognize Ag as well as how Ag are folded to present surfaces for Ag recognition. As such, the Ab surface holds information about Ag folding that resides with the Ab-Ag interface residues and how they interact. In order to gain insight into the nature of such interactions, a data set comprised of 53 non-redundant 3D structures of Ag-Ab complexes was analyzed. We assessed the physical and biochemical features of the Ag-Ab interfaces and the degree to which favored interactions exist between amino acid residues on the corresponding interface surfaces. Amino acid compositional analysis of the interfaces confirmed the dominance of TYR in the Ab paratope-containing surface (PCS), with almost two fold greater abundance than any other residue. Additionally TYR had a much higher than expected presence in the PCS compared to the surface of the whole antibody (defined as the occurrence propensity), along with aromatics PHE, TRP, and to a lesser degree HIS and ILE. In the Ag epitope-containing surface (ECS), there were slightly increased occurrence propensities of TRP and TYR relative to the whole Ag surface, implying an increased significance over the compositionally most abundant LYS>ASN>GLU>ASP>ARG. This examination encompasses a large, diverse set of unique Ag-Ab crystal structures that help explain the biological range and specificity of Ag-Ab interactions. This analysis may also provide a measure of the significance of individual amino acid residues in phage display analysis of Ag binding.
Sequence of peptides from Saccharomyces cerevisiae glutamine synthetase. N-terminal peptide and ATP-binding domain.
Sequences of seven tryptic peptides derived from Saccharomyces cerevisiae glutamine synthetase have been determined. The amino terminus of yeast enzyme is acetylated and has the following sequence: acetyl-Ala-Glu-Ala-Ser-Ile-Glu-Lys. Neither higher eukaryotic nor bacterial glutamine synthetase contain sequences homologous to this yeast amino terminus. 8-Azidoadenosine 5'-triphosphate [( alpha-32P]8-N3ATP) has been used to photolabel the ATP-binding site in yeast glutamine synthetase. Only one 32P-labeled tryptic peptide was obtained as a major fraction and its sequence is Glu-Gly-Tyr-Gly-X-Phe-Glu-Asp-Arg. Similar photolabeling experiments with bovine glutamine synthetase yielded a tryptic peptide whose sequence is Gly-X-Phe-Glu-Asp-Arg, where X is likely Tyr covalently attached by nitrene derived from [alpha-32P]8-N3ADP. Sequences very homologous to this nucleotide-binding site can be found in other eukaryotic enzymes but not in prokaryotic enzymes. In addition, the sequences of two cysteine-containing peptides and three other tryptic peptides were established. Sequences homologous to all these five peptides can be found in mammalian and plant enzymes. The homology between yeast and higher eukaryotic glutamine synthetases was sufficiently strong to suggest that the overall tertiary and quaternary structures of these enzymes must be similar. The sequences presented here, particularly the amino terminus sequence will be valuable in identifying the structural gene of yeast glutamine synthetase, thereby making it possible to study its transcriptional regulation. In addition, the sequences of the cysteine-containing peptides will be useful in determining whether or not the covalent modification of a sulfhydryl group(s) is responsible for the modulation of glutamine synthetase activity.
Role of Charged Amino Acids in Sullying the Fluorescence of Tryptophan or Conjugated Dansyl Probe in Monomeric Proteins.
When Trp/dansyl probe conjugated to a monomeric protein is photoexcited, it is assumed that all emitted fluorescence originates solely from them. In this work, we show that hidden unconventional intrinsic chromophores (called ProCharTS) that originate from confined charge clusters in the protein can contaminate Trp/dansyl emission. Previous work has shown that charge recombination among charge-separated excited states of monomeric proteins, rich in charged residues, can emit weak luminescence (300-700 nm) overlapping with ProCharTS absorption (250-800 nm) and Trp (300-400 nm) and dansyl (400-600 nm) emission. We examine how this overlap taints the fluorescence arising from Trp/dansyl. We compared the effect of dense aqueous solutions of amino acids, Lys/Glu/Asp/Arg/His, on the fluorescence intensity decay/spectrum of N-acetyl-l-tryptophan amide (NATA). Significant broadening on the red side of Trp emission spectrum was observed solely in the presence of lysine, which appeared to be the most potent in altering the mono-exponential fluorescence decay of NATA. Interestingly, NATA in the presence of proteins α3C and dehydrin (DHN1), which are rich in Lys residues, showed substantial deviation from mono-exponential fluorescence decay in contrast to PEST wt and Symfoil-4P pv2, which lack Lys residues. Remarkably, Trp emission spectra among charge-rich proteins like α3W, PEST M1, and DHN1 CW1 were altered on the red side of Trp emission. Emission spectrum of dansyl-labeled human serum albumin (HuSA) was broadened and its fluorescence quenched with gradual addition of excess unlabeled HuSA, which displays bountiful ProCharTS luminescence. Our results unveil the additive influence of ProCharTS luminescence on Trp/dansyl emission with no measurable evidence of energy transfer.
Novel nuclear autoantigen with splicing factor motifs identified with antibody from hepatocellular carcinoma.
A patient with liver cirrhosis who progressed to hepatocellular carcinoma was found to develop novel antinuclear antibodies. The serum was used to isolate full-length cDNA clones encoding related proteins of 530 amino acids (representative clone HCC1.4) and 524 amino acids (representative clone HCC1.3). Affinity-purified antibodies eluted from recombinant proteins recognized a 64-kD nuclear protein in Western blotting and decorated the nucleoplasm in a speckled-network fashion in immunofluorescence, colocalizing with antibodies to pre-mRNA splicing factor SC35 and uridine-rich small nuclear RNAs. The deduced amino acid sequence contained an arginine/serine-rich (RS) domain and three-ribonucleoprotein consensus sequence domains, two classes of motifs present in several splicing factors. A repeating octapeptide of Arg-Ser-Arg-Ser-Arg(Lys)-Glu(Asp)-Arg-Lys(Arg) was present in RS region of HCC1. This octapeptide sequence called RS-ERK motif was also found in splicing factors U2AF 35- and 65-kD proteins and 70-kD U1 small nuclear ribonucleoprotein. The molecular features and immunolocalization data suggest that the HCC1 autoantigen may be associated with splicing activities and are consistent with observations that autoantibody responses frequently target molecules involved in important cellular biosynthetic functions.
Quick links (PubMed)
- PMID 41490200 — 2026 · Therapeutic Peptides in Orthopaedics: Applications, Challenges, and Futu…
- PMID 24931192 — 2014 · Constitutive activity in gonadotropin receptors.
- PMID 18495483 — 2008 · Synthesis, nano-scale assembly, and in vivo anti-thrombotic activity of …
- PMID 22567179 — 2012 · Pinealon protects the rat offspring from prenatal hyperhomocysteinemia.
- PMID 26390612 — 2015 · [EFFECT OF SYNTHETIC PEPTIDES ON AGING OF PATIENTS WITH CHRONIC POLYMORB…
- PMID 21978084 — 2011 · Pinealon increases cell viability by suppression of free radical levels …
- PMID 36706884 — 2023 · Effect of seabuckthorn seed protein and its arginine-enriched peptides o…
- PMID 37754258 — 2023 · The Role of Amino Acids in the Diagnosis, Risk Assessment, and Treatment…
- PMID 22117547 — 2011 · Penetration of short fluorescence-labeled peptides into the nucleus in H…
- PMID 30762356 — 2019 · Role of Mono- and Divalent Ions in Peptide Glu-Asp-Arg-DNA Interaction.
- PMID 25051764 — 2014 · [Regulation of content of cytokines in blood serum and of caspase-3 acti…
- PMID 28539017 — 2016 · [Comparative analysis of different methods of geroprotective].
- PMID 39518916 — 2024 · Short Peptides Protect Fibroblast-Derived Induced Neurons from Age-Relat…
- PMID 26742748 — 2016 · Short Peptides and Telomere Length Regulator Hormone Irisin.
- PMID 33396470 — 2020 · EDR Peptide: Possible Mechanism of Gene Expression and Protein Synthesis…
- PMID 24738258 — 2013 · [Neuroprotective effects of peptides bioregulators in people of various …
- PMID 22708445 — 2012 · [Analysis of some parameters of biological age and adaptation possibilit…
- PMID 18546825 — 2008 · [Investigation of antihypoxic properties of short peptides].
- PMID 38944767 — 2024 · [Prospects for use of short peptides in pharmacotherapeutic correction o…
- PMID 28509493 — 2015 · [Pinealon and Cortexin influence on behavior and neurochemical processes…
- PMID 22977870 — 2012 · Tetrapeptide H-Ala-Glu-Asp-Arg-OH stimulates expression of cytoskeletal …
- PMID 25420772 — 2015 · Angiotensin II restricted analogs with biological activity in the erythr…
- PMID 23734521 — 2012 · [The peptide correction of neurotic disorders among professional truck-d…
- PMID 21809624 — 2011 · [Effects of introduction of short peptides before carotid artery occlusi…
- PMID 22803060 — 2011 · Effect of short peptides on expression of signaling molecules in organot…
- PMID 24909721 — 2014 · Short peptides stimulate serotonin expression in cells of brain cortex.
- PMID 22803085 — 2012 · Effect of bioregulatory tripeptides on the culture of skin cells from yo…
- PMID 10648631 — 2000 · Mutational analysis of the highly conserved arginine within the Glu/Asp-…
- PMID 28976148 — 2013 · [Effect of peptide geroprotectors on the navigation system learning and …
- PMID 31982792 — 2020 · Radiolabelling of lipid-based nanocarriers with fluorine-18 for in vivo …
- PMID 23581987 — 2013 · Interaction of short peptides with FITC-labeled wheat histones and their…
- PMID 9405602 — 1997 · Structure and function in rhodopsin: rhodopsin mutants with a neutral am…
- PMID 9880800 — 1999 · Subsite preferences of pepstatin-insensitive carboxyl proteinases from b…
- PMID 12803541 — 2003 · Gamma III-crystallin is the primary target of glycation in the bovine le…
- PMID 9144791 — 1997 · Curious structure in "canonical" alanine-based peptides.
- PMID 18546826 — 2008 · [Biological activity of regulatory peptides in model experiments in vitr…
- PMID 22246133 — 2012 · Antigen-antibody interface properties: composition, residue interactions…
- PMID 2891705 — 1988 · Sequence of peptides from Saccharomyces cerevisiae glutamine synthetase.…
- PMID 35107253 — 2022 · Role of Charged Amino Acids in Sullying the Fluorescence of Tryptophan o…
- PMID 8227358 — 1993 · Novel nuclear autoantigen with splicing factor motifs identified with an…