Matrikine

Matrikines are peptide fragments generated when an extracellular matrix protein is partly broken down by proteases, and which then function as signalling molecules themselves. The idea, set out formally by Maquart and co-workers during the 1990s, is that matrix breakdown is not purely destructive: the pieces carry messages, and hidden bioactive sites within the intact protein are exposed only once it has been cleaved.

Key examples

The most familiar are GHK from collagen and the KTTKS pentapeptide from type I procollagen; VGVAPG, derived from elastin, signals via the elastin receptor complex; and fragments from laminin and fibronectin are investigated in migration and angiogenesis assays. A number of endostatin- and tumstatin-type fragments are matrikines in the same sense and feature in angiogenesis research.

This mechanism is the direct rationale for cosmetic signal peptides: a topically applied matrikine is meant to show the skin the chemical fingerprint of matrix turnover and, according to the hypothesis, encourage fibroblasts to rebuild. Matrixyl — palmitoylated KTTKS — was designed on that basis. The evidence reported so far comes mostly from fibroblast culture and small clinical studies, and the link between fragment and response should be presented as a hypothesis still being tested.

Related terms and material

tripeptide · angiogenesis · tissue repair. Reference material: Matrixyl, Palmitoyl Tripeptide-1, cosmetic peptides. Further reading: peptides for skin research.