Vilon (Lys-Glu): What the Dipeptide Bioregulator Research Shows

Vilon is about as small as a peptide gets: two amino acids. That makes it a sharp test of the bioregulator hypothesis. If a dipeptide can carry a specific biological signal, the idea that short peptides act as gene regulators gains weight; if it cannot, the framework has a problem. This article covers what Vilon is, the mechanism proposed for it, what the studies report and in which models, and how strong that evidence is.

What Vilon is

Vilon is lysine joined to glutamic acid, written Lys-Glu or KE (molecular formula C11H21N3O5, molecular weight 275.30 g/mol, CAS 45234-02-4). It belongs to the bioregulator programme led by Vladimir Khavinson in St Petersburg and is assigned to the thymus and immune system. One basis for that assignment is the group's rat organ culture work, in which Vilon stimulated the growth of thymus tissue.

How Vilon relates to Thymalin, the calf thymus extract the programme began with, depends on which account you read. The group's 1997 overview describes Vilon as a novel dipeptide that was synthesised, in contrast to Thymogen (Glu-Trp), which was isolated from Thymalin. Later reviews state that Lys-Glu was detected in Thymalin by chromatography and mass spectrometry and then named Vilon, citing a 1997 Russian patent rather than a published analysis, and a 2023 paper calls KE one of Thymalin's active substances. Both accounts could be true, but we found no peer-reviewed analysis documenting the detection.

The proposed mechanism

The bioregulator model holds that a peptide this small can cross the cell and nuclear membranes and bind particular DNA sequences, changing which genes are read. For KE, most of the support is computational.

• Modelling: a 2019 study screened every possible dipeptide against every four-base DNA sequence. Most dipeptides could not bind DNA at all; among those with free ends, KE ranked first, with a predicted preference for the sequence TCGA. The authors concluded that only about 7% of dipeptides can bind DNA selectively, and then with moderate affinity.
• Test-tube binding: in a gel-shift test in the same study, KE shifted a short DNA fragment more than two dipeptides predicted not to bind. The peptide concentration was in the millimolar range, many orders of magnitude above the nanomolar concentrations used in the group's stem cell experiments.
• Moving targets: a 2023 docking study from the group predicted a different preferred site, GCGC, when DNA was modelled in its curved, nucleosome-wrapped form. Different DNA models can reasonably give different answers, but these remain predictions, not measurements of KE bound to a gene in a living cell.
• A common motif: Lys-Glu occurs throughout human proteins, and the group proposes that KE released when proteins are broken down could itself act as a signal. That raises a question the papers reviewed here do not answer: how a fragment this common could carry a tissue-specific message.

What the studies show

• Immune cells (cell culture): Lys-Glu increased interleukin-2 gene expression in mouse spleen lymphocytes, depending on concentration and time. In human blood immune cells from four donors stimulated with bacterial lipopolysaccharide, KE lowered the inflammatory cytokines IL-1β, IL-6 and TNF-α, as did Thymalin. In human mesenchymal stem cells, KE changed the expression of ageing-related genes such as FOXO1 and NF-κB, with some effects depending on the ageing model used.
• Chromatin (cells from older people): in cultured lymphocytes from older donors, a Tbilisi State University group working with Khavinson reported that Vilon loosened condensed heterochromatin and reactivated ribosomal genes.
• Mice and rats: a short 2000 report from the group described longer lifespan, more physical activity and fewer spontaneous tumours in female CBA mice given Vilon from six months of age. The fuller 2001 report on female CBA mice, which compared Vilon with Epitalon, attributed the significant survival gain to Epitalon; for Lys-Glu its abstract reports more physical activity and fewer spontaneous lung adenomas, but does not report a survival gain. In rats exposed to a bladder carcinogen, tumours developed in 56% of Vilon-treated animals against 75.5% of controls.
• Humans: small Russian-language reports describe Vilon added to standard treatment in people with type 1 diabetes, with changes in clotting and immune markers. The available abstracts describe no randomisation, blinding or placebo group.

How strong is the evidence?

Weak, and narrower than it first looks. Almost every Vilon study comes from Khavinson's institute or groups co-publishing with it, much of it in Russian-language journals, and PubMed turns up very little work on Lys-Glu as a bioregulator from unconnected laboratories. The mechanism rests on modelling and on binding in solution at concentrations far above those used in cells. The headline animal claim, longer life in mice, appears in a short 2000 report but not in the abstract of the fuller 2001 analysis. The human reports are small and uncontrolled.

A fair reading: Vilon shows immune-cell activity in the originating group's laboratory work, and it is a genuinely interesting test of whether a dipeptide can act as a gene regulator. That question remains open.

Where Vilon fits

Vilon is often studied alongside Epitalon, and it shares its thymus association with Thymalin. Vesugen (Lys-Glu-Asp) extends the same sequence by one residue. For how all the bioregulators fit together, see our guide to the Khavinson bioregulator peptides and the evidence behind them.

References

1. Khavinson VK. (2001). "Tissue-specific effects of peptides." Bulletin of Experimental Biology and Medicine. PubMed 11713572
2. Morozov VG, Khavinson VK. (1997). "Natural and synthetic thymic peptides as therapeutics for immune dysfunction." International Journal of Immunopharmacology. PubMed 9637345
3. Khavinson VKh. (2020). "Peptide medicines: past, present, future." Klinicheskaya Meditsina (in Russian). doi:10.30629/0023-2149-2020-98-3-165-177
4. Linkova N, et al. (2023). "The Influence of KE and EW Dipeptides in the Composition of the Thymalin Drug on Gene Expression and Protein Synthesis Involved in the Pathogenesis of COVID-19." International Journal of Molecular Sciences. PubMed 37686182
5. Kolchina N, et al. (2019). "Systematic search for structural motifs of peptide binding to double-stranded DNA." Nucleic Acids Research. PubMed 31598715
6. Ashapkin V, et al. (2020). "Gene expression in human mesenchymal stem cell aging cultures: modulation by short peptides." Molecular Biology Reports. PubMed 32399807
7. Terekhov AY, et al. (2020). "Peptide KE in Human Proteome." Bulletin of Experimental Biology and Medicine. PubMed 32246368
8. Khavinson VK, et al. (2000). "Effect of peptide Lys-Glu on interleukin-2 gene expression in lymphocytes." Bulletin of Experimental Biology and Medicine. PubMed 11177276
9. Lezhava T, et al. (2004). "Bioregulator Vilon-induced reactivation of chromatin in cultured lymphocytes from old people." Biogerontology. PubMed 15105581
10. Khavinson VK, et al. (2000). "Effect of vilon on biological age and lifespan in mice." Bulletin of Experimental Biology and Medicine. PubMed 11140587
11. Anisimov VN, et al. (2001). "Effect of synthetic thymic and pineal peptides on biomarkers of ageing, survival and spontaneous tumour incidence in female CBA mice." Mechanisms of Ageing and Development. PubMed 11163623
12. Pliss GB, et al. (2001). "Inhibitory effect of peptide vilon on the development of induced rat urinary bladder tumors in rats." Bulletin of Experimental Biology and Medicine. PubMed 11586406
13. Kuznik BI, et al. (2007). "Effect of vilon on the immunity status and coagulation hemostasis in patients of different age with diabetes mellitus." Advances in Gerontology (in Russian). PubMed 18306698