A matrikine is a peptide fragment released by partial proteolysis of an extracellular matrix protein that then acts as a signalling molecule in its own right. The concept, formalised by Maquart and colleagues in the 1990s, is that matrix degradation is not only destructive: the fragments carry information, and cryptic bioactive sites buried in the intact protein become accessible only after cleavage.
Examples and why they matter
Collagen-derived GHK and the KTTKS pentapeptide from type I procollagen are the best-known; elastin-derived VGVAPG acts through the elastin receptor complex; laminin-derived and fibronectin-derived fragments are studied in migration and angiogenesis assays. Several endostatin- and tumstatin-type fragments are matrikines in the same sense and appear in angiogenesis research.
The mechanistic logic is directly why cosmetic signal peptides exist: applying a matrikine is intended to present the skin with the chemical signature of matrix turnover and, per the hypothesis, prompt fibroblasts to rebuild. Matrixyl is palmitoylated KTTKS on that reasoning. Reported support is mostly fibroblast culture and small clinical studies, and the fragment-to-response link should be described as a hypothesis under test.
Related terms and material
tripeptide · angiogenesis · tissue repair. Reference material: Matrixyl, Palmitoyl Tripeptide-1, cosmetic peptides. Further reading: peptides for skin research.