摘要

By 30% - 60% (NH4)(2)SO4 fractional precipitation, anion-exchange chromatography on DEAE-Sepharose CL-6B, gel filtration on Sephacryl S-200 and anion-exchange chromatography on Waters AP-1 column (Protein(PM)-Pak DEAE 15HR), a proteinase which can inactivate soybean trypsin inhibitor (STI) was purified from mung bean ( Vigna rabiata (L.) Wilezek) sprouts. Its molecular weight was estimated to be 29.8 kD by SDS-PAGE, and its K-m and V-max for STI were 769.2 N-alpha -benzoyl-L-arginine ethyl ester BAEE/mL and 115.3 BAEE . mL(-1) . min(-1) respectively. This proteinase was stable at temperatures lower than 50 degreesC and pH 6.5 - 8.5, and 90.91% STI activity of defatted soybean powder was inactivated by this preparation, with proteolytic activity 5 000 BAEE/mL at 50 degreesC and pH 8.0 in 4 h.