Collagenolytic activity from isolated bone cells.

A true collagenase (EC 3.4.24.3) which had been discovered previously in bone culture fluids and extracts of whole bone has now been localized to the cellular component of bone. The cellular enzyme bears the same characteristics as that of bone collagenases described earlier. Moreover, it is directly extractable in relatively large quantities. Attempts to demonstrate the presence of a bone cell procollagease were unsuccessful. It was also observed that the cells secrete significant amounts of collagenase in vitro. With increasing incubation time the extracellular collagenase levels rise and the intracellular collagenase levels drop.