Peptide Database

Human Neutrophil Peptides (HNP-1, HNP-2, HNP-3) · α-defensins

Alpha-defensins are cationic antimicrobial peptides secreted by neutrophils (HNP-1 to 4) and Paneth cells (HD-5, HD-6) in the small intestine. They kill bacteria, fungi, and enveloped viruses through membrane disruption and also function as chemokines, recruiting immune cells and bridging innate and adaptive immunity. Paneth cell alpha-defensins (HD-5, HD-6) play a critical role in shaping intestinal microbiome composition.

Leu-Enkephalin · Met-Enkephalin

Enkephalins are endogenous opioid pentapeptides (Met-enkephalin and Leu-enkephalin) acting as natural ligands for delta and mu opioid receptors. They modulate pain, mood, reward, and immune function. Low-dose naltrexone (LDN) works partly by transiently blocking opioid receptors to upregulate enkephalin production. Methionine enkephalin (met-enkephalin) has shown immune-modulating and anti-tumor properties in research, particularly for HIV and cancer.

Lys-Pro-Val · α-MSH C-terminal tripeptide

KPV is a tripeptide derived from the C-terminal sequence of alpha-melanocyte-stimulating hormone (α-MSH). It exhibits potent anti-inflammatory effects by inhibiting NF-κB signaling and proinflammatory cytokine production. Research is particularly focused on its potential for inflammatory bowel disease, colitis, and skin inflammation, with studies showing efficacy even when administered orally or topically.

Serum Thymic Factor · Facteur Thymique Sérique

Thymulin is a nonapeptide produced exclusively by thymic epithelial cells, requiring zinc for biological activity. It promotes T-cell differentiation, enhances cytokine production, and is a key marker of thymic function. Circulating thymulin levels decline with age, paralleling thymic involution. Research examines its role in autoimmunity, inflammatory diseases, and as a zinc-dependent immune regulator in aging.

Lys-Glu · KE dipeptide

Vilon is a synthetic dipeptide (Lys-Glu) developed at the St. Petersburg Institute of Bioregulation and Gerontology as a vascular cytoprotective peptide. Research demonstrates it reduces vascular endothelial cell aging, suppresses excessive collagen synthesis, and modulates the renin-angiotensin system. Long-term animal studies show improved vascular function and survival; it is often studied as part of peptide longevity protocols.