Purification and characterization of the trypsin-like serine endo-peptidase from Paecilomyces farinosus

Abstract

A protease was partially purified from the culture filtrate of a plant worm, Paecilomyces farinosus. The activity of the protease was suppressed by serine protease inhibitors, such as phenylmethylsulfonyl fluoride, soybean trypsin inhibitor, aprotinin, and leupeptin. Its molecular mass was estimated to be 33 kDa by SDS-PAGE, and its optimal pH and temperature were pH 8.0 and 45°C, respectively. The N-terminal amino acid sequence of the protease was IVGGDDAEIAEYPY-. The amino acid sequence shares sequence homology with the trypsin-like serine endopeptidase belonging to the peptidase S1 family from Aspergillus nidulans and Drosophila erecta. From these results, it was considered that the enzyme from P. farinosus is a trypsin-like serine endopeptidase.