Characteristics of a proteinase of a trichosporon species isolated from Dungeness crab meat

Abstract

The proteinase of a Trichosporon species was partially purified by dialysis, ammonium sulfate fractionation, and Sephadex G-100 gel filtration. A 170-fold purification of the enzyme with a 1.4% recovery of the activity was achieved. The proteinase was separated into a major component and possibly two minor components by starch gel electrophoresis. The pH optimum of the enzyme was 5.8 to 6.2. It was active against casein, hemoglobin, and crab protein substrates, but inactive against bovine serum albumin, lysozyme, and benzoylarginine ethyl ester. It was slightly activated by 10 mm cysteine, 0.1 mm ethylenediaminetetraacetic acid, and 0.1 mm Co(++). There was slight inhibition by 10 mm Co(++) and 0.1 mm phenylmethylsulfonylfluoride, and total inhibition by 1 mmp-chloromercuribenzoate. The proteinase was completely inactivated by heating at 60 C for 10 min.