Abstract
A proteinase of Mr 27,000 with a possible role in the metabolism and invasion of host tissues was purified from the conditioned medium of Trichophyton rubrum by concanavalin A and anion-exchange chromatography. Peaks of proteolytic activity were analyzed by substrate gel electrophoresis. The 27,000-Mr proteinase had a pH optimum of 8.0, a calcium dependence of 2 mM, and was inhibited by serine proteinase inhibitors, especially phenylmethylsulfonyl fluoride and Phe-Gly-Ala-Leu-chloromethyl ketone. By polyacrylamide gel electrophoresis, the 27,000-Mr proteinase had a reduced molecular weight of 44,000 and reacted with [3H]diisopropyl fluorophosphate. The proteinase degraded azocoll, type III collagen, type IV procollagen, laminin, fibronectin, and the peptide substrates succinyl-Ala-Ala-Pro-Phe-p-nitroanilide (1,573 M-1 s-1) and t-butyloxy carbonyl-Ala-Ala-Leu-p-nitroanilide (1,614 M-1 s-1).