Lens calcium activated proteinase: degradation of vimentin

The lens has been shown to contain a Ca+2 activated proteinase specific for vimentin. The proteinase is present in the soluble fraction of the cortex but not in the epithelium. It is suggested that this proteinase is expressed during terminal differentiation of the epithelial cells and may be responsible for degradation of the intermediate filaments in the fiber cells. The proteinase is inhibited by EGTA but not by several proteinase inhibitors.