Collagen solubilization by mammalian proteinases

Collagen is sometimes rapidly metabolized in vivo, but clear evidence of proteolysis by tissue enzymes has been lacking. In this study, the solubilization and proteolysis of washed, dissected collagen fibers from rat tail tendons were examined at 38 ° and pH 7.4 under the influence of chemicals to which collagen may be exposed in vivo. Trypsin, chymotrypsin, elastase, and the endopeptidase from procarboxypeptidase all solubilized collagen in the presence of calcium salts or salicylates. Arginine, creatinine, and guanidine enhanced this solubilization and lowered the calcium and salicylate levels required. The adsorptive capacity of some collagens, particularly for calcium, suggests that adequate concentrations of sensitizing agents could occur locally in vivo.