Synthesis of collagenase inhibitor by KB cells.

Collagenase inhibitor has been characterized and identified in a variety of connective tissues. This paper reports the purification and characterization of the collagenase inhibitor secreted by KB cells in culture.Results were as follows:1. KB cells in the serum free culture medium secreted collagenase inhibitor.2. Collagenase inhibitor was divided into two peaks by CM-52 column chromatography.Molecular weights of the inhibitor were estimated to be 32, 000 and 16, 500 by gel filtration.3. The addition of the inhibitor to activated collagenase resulted in a dose-dependent inhibition of the enzyme activity.4. The KB cell inhibitor showed inhibitory activity against all the animal collagenase tested except for bacterial collagenase.5. Trypsin, thermolysin and elastase were not inhibited by the KB cell inhibitor.6. The collagenase inhibitory activity was stable after treatment with APMA (1 mM) at 35°C for 3 h., after incubation for 30 min. at 60°C, but was lost by reductive alkylation.