Description

Livagen Peptide

 

 

CAS Number	195875-84-4
Other Names	Livagen
IUPAC Name	(2R,3S)-3-(3,4-Dichlorophenyl)-2-(ethoxymethyl)-8-methyl-8-azabicyclo[3.2.1]octane
Molecular Formula	C₁₈H₃₁N₅O₉
Molecular Weight	461.5
Purity	≥99% Pure (LC-MS)
Liquid Availability	N/A
Powder Availability	10 milligrams vial (lyophilized/freeze-dried)
Storage Condition	Store cold, keep refrigerated. Do NOT freeze.
Terms	All products are for laboratory developmental research USE ONLY. Products are not for human consumption.

**Important Information: Each peptide comes lyophilized/freeze-dried and must be reconstituted with Bacteriostatic Water in order to be dispensable in liquid form.

Watch How To Reconstitute Peptide Video Here

 

What is Livagen?

 

Livagen is a short regulatory peptide derived from the thymus that has been studied for its potential role in modulating gene expression and promoting cellular repair processes. Belonging to the class of cytomedines, naturally occurring peptides that regulate tissue-specific functions, Livagen is thought to influence chromatin structure and DNA methylation, resulting in restored cellular activity in aging or damaged tissues. Research suggests that it may enhance cellular metabolism, support immune regulation, and contribute to the maintenance of genomic stability, making it of interest in gerontology, regenerative medicine, and epigenetic therapy.

 

Main Research

1) Livagen was found to modify heterochromatic and heterochromatinized regions in chromosomes by activating chromatin in lymphocytes of aged individuals.

2) Administration of Livagen was shown to activate and deheterochromatinize precentromeric and telomeric heterochromatin in the cells of aged individuals.

 

 

Selected Data
1) In this study, researchers Khavinson et al investigated the effects of the peptide Livagen on chromosomal and chromatin structures in human lymphocytes obtained from 23 conventionally healthy elderly donors aged 76 to 80 years. Each donor provided lymphocyte samples that were divided into two groups, intact (control) cultures and Livagen-treated cultures, allowing for direct comparison between treated and untreated cells within the same individual. The study aimed to assess whether Livagen could influence the structural and functional characteristics of chromatin, including ribosomal gene activity, heterochromatin organization, and chromosomal polymorphism, without inducing mutagenic effects [1].
A total of 1,040 metaphases were analyzed, derived from 15 intact and 15 Livagen-treated lymphocyte cultures. Additionally, differential scanning microcalorimetry (DSM) was carried out on 4 control and 8 Livagen-treated cultures to measure thermal stability changes in chromatin components. Livagen was administered at a concentration of 0.005 μg/ml, a dose previously shown to have no mutagenic activity.
The activity of ribosomal genes was evaluated through multiple cytogenetic indicators: the frequency of acrocentric chromosome associations, the number of nucleolar organizer regions (NORs) in these acrocentric chromosomes, and the intensity of silver staining (Ag-NOR staining). NORs are chromosomal regions associated with ribosomal RNA gene clusters, and their activity reflects the transcriptional state of ribosomal genes. By comparing these parameters between intact and Livagen-treated lymphocytes, the researchers could determine whether Livagen influenced ribosomal gene expression or chromosomal interactions. Statistical comparison of NOR frequency and acrocentric associations between treated and untreated cultures was performed using the binomial population test to assess the significance of observed differences [1].
To study heterochromatin structure and stability, the researchers employed DSM, a method that measures the thermal denaturation of chromatin components. The technique is based on the principle that different chromatin fractions, such as euchromatin and heterochromatin, have distinct thermostability properties. The DSM measurements were performed across a temperature range of 20 to 150°C, with a heating rate of 35°C per hour, and a sensitivity of 10⁻⁷ cal/min. The instrument’s measuring cell had a volume of 0.3 ml. By analyzing the temperature-dependent heat absorption patterns, researchers could identify structural differences in chromatin stability between control and Livagen-treated samples, indicating possible peptide-induced changes in chromatin organization or composition.
The structural polymorphism of constitutive C-heterochromatin, regions of the chromosome that are usually transcriptionally inactive but structurally important, was also examined. This was done using C-banding, a standard cytogenetic technique that selectively stains regions rich in constitutive heterochromatin. The study compared the C-band patterns of chromosomes 1, 9, and 16 between control and Livagen-treated lymphocytes, using the short arm of chromosome 16 as a reference for segment size. The variations in heterochromatin size and morphology were classified into five categories, a, b, c, d, and e, and statistical analysis of these distributions was conducted using Zaks’ formula for χ² (chi-squared) calculations. This analysis helped determine whether Livagen altered the structural organization or variability of C-heterochromatin regions across different chromosomes [1].
In addition to structural heterochromatin analysis, the study also assessed facultative heterochromatin variability through measurement of sister chromatid exchanges (SCEs). SCEs are exchanges of DNA segments between sister chromatids during replication, often used as indicators of genomic instability or repair activity. To visualize these exchanges, cells were incubated with 5-bromodeoxyuridine (BrdU) at a final concentration of 7.7 μg/ml for two cell replication cycles, followed by differential staining of sister chromatids using a method that did not require fluorochromes. The mean number of SCEs per metaphase was calculated for both intact and Livagen-treated lymphocytes. Any differences in SCE frequency were evaluated statistically using Student’s t-test, allowing determination of whether Livagen exerted a stabilizing or destabilizing effect on DNA replication and repair processes [1].
Overall, this carefully controlled study used a combination of cytogenetic, biochemical, and biophysical techniques to characterize how Livagen affects chromatin structure and ribosomal gene activity in human lymphocytes from elderly donors. Through parameters such as NOR activity, heterochromatin polymorphism, chromatin thermostability, and SCE frequency, the research sought to clarify whether Livagen contributes to maintaining genomic stability and proper chromatin function in aging cells without introducing mutagenic effects [1].

2) This study performed by Lezhava et al investigated the effects of the peptide Livagen, both alone and in combination with cobalt chloride (CoCl₂), on chromatin structure, chromosomal stability, and DNA repair processes in human lymphocytes from young and elderly donors. Researchers compared cellular responses between 14 healthy older individuals aged 80–91 years and 14 healthy young controls aged 18–30 years, examining how aging and experimental treatments influenced chromatin condensation, mutagenic susceptibility, and chromosomal repair activity. In total, 52 lymphocyte cultures were prepared from each age group, with each donor contributing four types of samples: untreated control cultures, cultures treated with Livagen alone, cultures treated with CoCl₂ alone, and cultures treated with both Livagen and CoCl₂ [2].
The bioregulator Livagen used in this research is a synthetic tetrapeptide with the amino acid sequence Lys-Glu-Asp-Ala, developed through targeted chemical synthesis. The design of this peptide was based on the amino acid composition of a liver-derived bioregulatory complex. Previous experimental work has demonstrated that Livagen enhances protein synthesis in aged animals, restores normal liver protein composition, and stimulates hepatocyte activity in older rats. These findings suggest that Livagen exerts a regenerative and protein-synthetic effect, making it a promising candidate for studying age-related chromatin and genomic regulation.
To assess chromosome heterochromatinization, the researchers used differential scanning microcalorimetry (DSM), a highly sensitive biophysical technique capable of detecting conformational changes in macromolecular structures by measuring heat absorption during thermal denaturation. DSM analyses were performed on 24 lymphocyte cultures from eight individuals representing both middle-aged and elderly groups. The measurements were carried out with a calorimetric sensitivity of 10⁻⁷ cal/s, covering a temperature range of 20–150°C and using a scanning rate of 35 K/h in a 0.3 mL measurement cell [2].
Previous microcalorimetric investigations of various biological materials, including tissues, cells, and isolated nuclei, have shown that the thermal denaturation process of cellular components is characterized by distinct heat absorption peaks corresponding to specific structural transitions. According to earlier studies, cell membranes, cytoplasmic structures, and nuclear proteins denature within the 40–70°C range, while chromatin displays several well-defined denaturation peaks at approximately 60°C, 76°C, 88°C, and 105°C. These peaks represent the melting of different hierarchical chromatin structures such as nucleosomes, 30-nm solenoids, and supercoiled DNA loops. By analyzing these temperature-dependent heat absorption patterns, the researchers were able to assess whether Livagen and CoCl₂ altered the conformational stability of chromatin, thus revealing potential age-related or treatment-induced differences in chromatin condensation and decondensation [2].
The study also evaluated the mutagenic potential and protective effects of Livagen under conditions of heavy metal exposure. For this purpose, chromosomal aberrations were analyzed in lymphocytes treated with CoCl₂, either alone or combined with Livagen. Cobalt chloride, used at a concentration of 0.5 × 10⁻⁴ M, served as a chemical stressor known to induce oxidative and genotoxic effects, while Livagen was added at concentrations ranging from 0.005 to 0.01 μg/mL. Both agents were introduced at the start of the 50-hour lymphocyte cultures. Cytogenetic analysis was performed on 723 metaphases from 20 lymphocyte cultures derived from five elderly individuals between 80–91 years old, and on 645 metaphases from 20 cultures obtained from five young individuals between 18–30 years old. This allowed for standardized identification of chromosomal abnormalities such as breaks, gaps, and exchanges, which served as indicators of mutagenic or protective responses to the treatments.
To examine chromosomal repair mechanisms, the study measured variability in facultative heterochromatin by quantifying sister chromatid exchanges (SCEs), a cytogenetic marker reflecting DNA repair and recombination activity. The analysis involved 695 metaphases from 20 lymphocyte cultures obtained from five elderly individuals and 600 metaphases from 20 cultures from five young donors. These cultures included untreated controls as well as cells exposed to CoCl₂, Livagen, or their combination. To visualize SCEs, all cultures were incubated with 5-bromodeoxyuridine (BrdU) at a final concentration of 7.7 μg/mL for two cell replication cycles. The chromosomes were then differentially stained without fluorochromes, following the method of Antoshchina and Poryadkova, allowing for clear differentiation of sister chromatids and accurate counting of exchange events [2].
By integrating these methods, including DSM for conformational analysis, cytogenetics for mutation assessment, and SCE testing for DNA repair capacity, the study provided a comprehensive evaluation of Livagen’s biological effects. The design enabled researchers to determine whether Livagen could mitigate CoCl₂-induced chromosomal damage, promote chromatin decondensation, and enhance repair-associated chromosomal exchanges, thereby offering insight into its potential anti-aging and genome-stabilizing properties in human lymphocytes [2].

 

Discussion

1) This study performed by Khavinson et al examined how the peptide Livagen influences chromatin structure, ribosomal gene activity, and heterochromatin organization in lymphocytes derived from elderly human donors. Using cytogenetic and microcalorimetric analyses, the researchers demonstrated that Livagen induces chromatin decondensation, activates ribosomal genes, and alters heterochromatin structure, suggesting that it reverses some of the repressive chromatin modifications associated with cellular aging [1].
Through Ag-NOR staining, the researchers observed that ribosomal genes responsible for protein synthesis are localized in the secondary constrictions of satellite threads of acrocentric chromosomes. When two such threads are present, acrocentric chromosomes form associations, reflecting active ribosomal gene transcription. Positive Ag staining marks NORs, which remain functionally active during interphase. The intensity of silver staining directly correlates with the activity of ribosomal genes as more intense staining indicates higher transcriptional activity. Conversely, the absence of satellite threads signifies inactivation of ribosomal genes.
Treatment with Livagen led to a significant increase in both the number and intensity of Ag-positive NORs within individual acrocentric chromosomes and their associations. Quantitative analysis revealed that the mean number of Ag-positive NORs per cell was markedly higher in Livagen-treated lymphocytes compared to untreated controls. Furthermore, the peptide increased the frequency of acrocentric chromosome associations, reflecting elevated transcriptional and synthetic activity. This enhancement occurred uniformly across different types of chromosomal associations, such as DD, DG, and GG. These findings are consistent with earlier studies showing that hormones and growth factors can induce chromosome decondensation and upregulate NOR activity. Together, the data indicate that Livagen promotes de-heterochromatinization of satellite regions and reactivation of ribosomal genes in the lymphocytes of older individuals [1].

Figure 1: Number of Ag-positive NORs and number of cell associations in lymphocyte cultures in control (light) and Livagen-treated (dark) cultures.
Using DSM, the researchers next analyzed how Livagen affected the thermal denaturation properties of chromatin. In untreated lymphocytes, the heat absorption curve displayed three major endothermic peaks and several minor “shoulders,” corresponding to the stepwise denaturation of cellular and chromatin structures. The low-temperature peaks ranging from 46–63°C, represented denaturation of membranes, the nuclear matrix, and cytoplasmic components, while the higher temperature peaks around 71°C and beyond reflected the denaturation of chromatin substructures, including the 10-nm nucleosomal filament, the 30-nm solenoid fiber, and higher-order supercoiled loops attached to the nuclear matrix.
In contrast, Livagen-treated cells showed significant shifts in the calorimetric profile. Specifically, there was a shift in heat absorption peak II and the disappearance of endotherm III, along with an overall increase in heat absorption intensity between 53–67°C. These thermal changes indicate that Livagen causes uncoiling of dense chromatin filaments, producing more relaxed chromatin fibrils with separated nucleosomes that denature in three distinct stages at approximately 56°C, 70°C, and 75°C. The increased heat absorption in the 53–67°C range likely corresponds to denaturation of linker DNA regions, which are weakly protected by histone H1. This suggests that Livagen promotes chromatin loosening by displacing histone interactions and enhancing nucleosomal mobility, leading to decondensation of chromosomal material in aging lymphocytes [1].
Cytogenetic analysis of C-heterochromatin further revealed that Livagen reduced the size of large C-segments, classified as d and e, and increased the frequency of small C-segments, defined as a and b. Detailed examination of chromosomes 1, 9, and 16 showed that Livagen caused heteromorphism in chromosomes 1 and 9, indicating variability and decondensation of their heterochromatic regions. The size distribution of heterochromatin in chromosome 16, however, remained unchanged. These findings align with previous reports that certain chemical agents can reduce the size of C-heterochromatin in chromosomes 1 and 9 but not 16. Thus, Livagen appears to selectively decondense structural chromatin, particularly in chromosomes prone to age-related heterochromatin expansion [1].
Finally, the study evaluated SCEs, a marker of DNA repair and chromatin dynamics. Livagen treatment increased the average number of SCEs per cell across nearly all chromosome groups, with the exception of group F composed of chromosomes 19 and 20, where the effect was insignificant. Since SCEs are typically absent in tightly packed heterochromatic regions, the increase in SCE frequency indicates that Livagen decondenses chromatin, rendering previously repressed euchromatic regions accessible for transcription and recombination.
Overall, the findings demonstrate that Livagen activates chromatin in lymphocytes from elderly individuals by modifying both constitutive and facultative heterochromatin regions. Through mechanisms involving chromatin decondensation, NOR activation, and structural remodeling of heterochromatin, Livagen appears to reactivate silenced genes and counteract age-related chromatin repression, suggesting potential epigenetic rejuvenating effects at the cellular level [1].
2) This study conducted by Lezhava et al investigates the influence of the peptide bioregulator Livagen on chromatin structure, chromosomal stability, and SCE in lymphocyte cultures derived from middle-aged and elderly individuals, both in the presence and absence of cobalt ions. The findings demonstrate that Livagen can induce deheterochromatinization, or chromatin decondensation, in aged cells, counteracting the age-related condensation of chromatin and associated decline in genomic activity. The research also explores how metal ions like cobalt affect chromosomal integrity and how Livagen modifies these effects [2].
Thermal denaturation analysis revealed distinct heat absorption peaks corresponding to the unfolding of various cellular structures. In intact cell cultures from aged individuals, three main endothermic peaks, around 46°C, 55°C, and 63°C, were associated with the denaturation of membrane, nuclear matrix, and cytoplasmic components. Higher temperature peaks at approximately 80°C, 98°C, and 107°C reflected the denaturation of different levels of chromatin organization, such as nucleosomes within fibrils, the 30-nm solenoid structure, and super-condensed chromatin loops attached to the nuclear matrix. Treatment with Livagen altered this pattern: in both unstimulated and phytohemagglutinin (PHA)-stimulated lymphocytes, the highest-temperature endothermic peak (corresponding to the most condensed chromatin) disappeared, and the lower peaks shifted toward higher temperatures ranging from 53–67°C. These changes indicated that Livagen induced partial unfolding of tightly packed chromatin fibrils, promoting a more relaxed, transcriptionally active chromatin state. In summary, Livagen was shown to deheterochromatinize total chromatin, including both facultative and structural heterochromatin, in lymphocytes from aged individuals [2].
The next part of the study examined how Livagen and Co²⁺ ions, alone or together, affected chromosome damage in lymphocytes from middle-aged and old individuals. In untreated cultures, the frequency of chromosomal aberrations was significantly higher in elderly cells at 4.2% compared to middle-aged ones at 1.7%. Exposure to CoCl₂ substantially increased chromosomal damage in both groups to 8.5% and 13.2%, respectively. The most common abnormalities included single and paired fragments and terminal chromatid deletions, with older cells being more sensitive to metal-induced genotoxicity. Interestingly, Livagen alone did not increase chromosomal disturbances; rather, it slightly reduced aberration frequencies in both age groups. More notably, when combined with Co²⁺, Livagen demonstrated a strong antimutagenic effect, lowering chromosomal aberrations to 2.2% in middle-aged and 3.4% in elderly individuals. This finding suggests that Livagen protects the genome from metal-induced damage, likely through chromatin structure modulation.

Figure 2: Changes in chromosome damage induced by heavy metal and Livagen exposure in lymphocytes cultures collected from aged individuals
The study also analyzed sister chromatid exchange (SCE) frequencies and their distribution among chromosomes and chromosomal regions. CoCl₂ alone did not significantly affect SCE frequency in either young or old individuals. However, when combined with Livagen, a slight increase in SCE frequency was observed. SCEs predominantly occurred in the medial regions of chromosomes (~92%), with fewer in pericentromeric (5%) and telomeric (3%) regions. In aged cells, cobalt ion exposure alone increased SCEs in pericentromeric heterochromatin, while the combination of cobalt ion and Livagen raised SCEs in telomeric heterochromatin. This shift suggested that both CoCl₂ and Livagen altered the structural conformation of heterochromatin, making these typically condensed and transcriptionally silent regions more accessible and active [2].
The authors emphasized that changes in chromatin condensation play a crucial role in epigenetic regulation of gene expression. Heterochromatin, characterized by tightly packed nucleosomes and hypoacetylated histones, is transcriptionally inactive, whereas euchromatin, which is less condensed and more acetylated, supports active transcription. With aging, human chromosomes become progressively more heterochromatinized, leading to gene silencing and reduced DNA repair capacity. The study’s findings indicate that Livagen can reverse this process by inducing chromatin decondensation, reactivating previously silenced genomic regions.
Mechanistically, heterochromatin formation involves histone methylation, recruitment of heterochromatin proteins such as HP1, and regulation by small noncoding RNAs. These layers of regulation contribute to the structural and functional compartmentalization of the genome. With aging, excessive heterochromatinization disrupts these processes, increasing mutation rates and reducing gene expression. Livagen, by promoting chromatin relaxation, may restore transcriptional activity in regions affected by age-related silencing [2].
Further, the study connected Livagen’s effects with telomere biology. Age-dependent telomere shortening, approximately 50–150 base pairs per cell division, is associated with chromosomal instability, impaired DNA repair, and decreased cellular function. The authors propose that Livagen’s deheterochromatinizing influence extends to pericentromeric and telomeric heterochromatin, potentially reactivating telomerase-coding genes and stabilizing telomere length. Supporting evidence from related peptide bioregulators such as Epitalon showed that treated cells with elongated telomeres were able to undergo additional divisions, suggesting rejuvenation at the chromosomal level.
In conclusion, the study provides compelling evidence that Livagen induces reactivation of heterochromatinized chromosomal regions in lymphocytes from aged individuals. Through its decondensing action, Livagen enhances chromatin accessibility, promotes SCE formation in previously inactive regions, and counteracts metal ion–induced genotoxicity. The peptide’s combined effects with CoCl₂ highlight its potential to restore gene expression, stabilize chromosomal integrity, and influence telomere maintenance. Overall, Livagen appears to reverse key aspects of age-related chromatin condensation, representing a promising tool for mitigating genomic instability and functional decline in aging cells [2].

 

Disclaimer

**LAB USE ONLY**
*This information is for educational purposes only and does not constitute medical advice. THE PRODUCTS DESCRIBED HEREIN ARE FOR RESEARCH USE ONLY. All clinical research must be conducted with oversight from the appropriate Institutional Review Board (IRB). All preclinical research must be conducted with oversight from the appropriate Institutional Animal Care and Use Committee (IACUC) following the guidelines of the Animal Welfare Act (AWA).

 

Citations

[1] Khavinson VKh, Lezhava TA, Monaselidze JG, et al. Effects of Livagen peptide on chromatin activation in lymphocytes from old people. Bull Exp Biol Med. 2002;134(4):389-392. doi:10.1023/a:1021924702103

[2] Lezhava T, Jokhadze T. Activation of pericentromeric and telomeric heterochromatin in cultured lymphocytes from old individuals. Ann N Y Acad Sci. 2007;1100:387-399. doi:10.1196/annals.1395.043

 

 

PEPTIDES PREFER THE COLD
Keep peptide vials refrigerated at all times to reduce peptide bond breakdown. DO NOT FREEZE. Most peptides, especially shorter ones, can be preserved for weeks if careful.
Always swab the top of the vial with an alcohol wipe, rubbing alcohol or 95% ethanol before use.
Before drawing solution from any dissolved peptide vial, fill the pin with air to the same measurement you will be filling with solution, ie. if you plan to take 0.1 ml, first fill the pin with 0.1ml of air, push the air into the vial, and then draw the peptide back up to the 0.1 ml marker. Doing so will maintain even pressure in the vial. Always remember to remove air bubbles from the pin by flicking it gently, pin side up, and pushing bubbles out. In addition, push out a tiny amount of solution to ensure there is no air left in the metal tip.

ONLY MIX WITH STERILE BACTERIOSTATIC WATER
The purity and sterility of bacteriostatic water are essential to prevent contamination and to preserve the shelf-life of dissolved peptides.
Push the pin through the rubber stopper at a slight angle, so that you inject the bacteriostatic water toward the inside wall of the vial, not directly onto the powder.
Lyophilized peptide should be stored at -20°C (freezer), and the reconstituted peptide solution at 4°C (refrigerated). Do not freeze once reconstituted.
NEVER SHAKE A VIAL TO MIX.

Air bubbles are unfavorable to the stability of proteins.

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