Isolation and characterization of a trypsin-like protease from Trichodermaviride

A serine endopeptidase with a molecular mass of 25 kDa has been purified fr om the culture filtrate of Trichoderma viride to electrophoretic homogeneit y. The isoelectric point was determined at 7.3. Two carboxyl sites at Arg22 and Lys29 of the oxidized insulin B-chain were cleaved, and peptidyl-p-nit roanilide substrates with Lys or Arg at the P1 position were also hydrolyze d by the enzyme. These results suggest that the specificity of T. viride pr otease is similar to that of trypsin. However, the hydrolytic activity toward casein of T viride protease was les s than that of porcine trypsin. The amino-terminal sequence of the enzyme p rotein is similar to that of bovine trypsin. It seems that the trypsin of T viride is a protease which is promising for the substitution of animal try psin in the food industry and in medicine at this stage.