Collagen fibril formation is associated with the oxidation of specific lysine and hydroxylysine residues by the extracellular enzyme lysyl oxidase.

This results in cross-linking between the chains of adjacent molecules, thus stabilizing the array that is characteristic of collagen (collagen cross-linking). Cross-linking is a major contributor to the tensile strength of collagen.

Vitamin C is required for the hydroxylation of procollagen, a requirement that explains the inadequate wound healing in scurvy.

See also

 protein cross-linking