Inter- and Intramolecular Cross-linking in Tyrosinase-treated Tropocollagen

Abstract

Abstract Tropocollagen solutions treated with mushroom tyrosinase developed a yellow-brown color and showed a large increase in viscosity. Spectral and fluorescence studies revealed the oxidation of tyrosine residues in collagen. Viscosity, sedimentation, and polarimetric studies showed that tyrosinase action on collagen resulted in inter- and intramolecular cross-linking of tropocollagen molecules. Protease treatment abolished most of the sites of tyrosinase action in tropocollagen. The results suggest that tyrosine residues in collagen are integral parts of the tropocollagen primary structure and that they are mainly located on protease-susceptible peptide appendages (telopeptides) so strategically located that they play important roles in intermolecular interactions.