Cross-Linking of Collagen

Science  11 May 1973:
Vol. 180, Issue 4086, pp. 561-566
DOI: 10.1126/science.180.4086.561


The formation of collagen cross-links is attributable to the presence of two aldehyde-containing amino acids which react with other amino acids in collagen to generate difunctional, trifunctional, and tetrafunctional cross-links. A necessary prerequisite for the development of these cross-links is that the collagen molecules be assembled in the naturally occurring fibrous polymer. Once this condition is met, cross-linking occurs in a spontaneous, progressive fashion. The chemical structures of the cross-links dictate that very precise intermolecular alignments must occur in the collagen polymer. This seems to be a function of each specific collagen because the relative abundance of the different cross-links varies markedly, depending upon the tissue of origin of the collagen.