Biochemical Characterization of a Low Trypsin Inhibitor Soybean

Abstract

ABSTRACT A low trypsin inhibitor soybean (LTI) was characterized using electrophoresis, enzyme activity measurements, and gel exclusion chromatography. The protein profiles were similar to a control soybean. Gel exclusion chromatography resulted in two peaks of trypsin inhibitor activity in the control. The first peak, absent in LTI, proved to be Kunitz trypsin inhibitor and was electrophoretically isomorphic. The second inhibitor consisted of at least five isotypes and co‐eluted with Bowman‐Birk trypsin inhibitor. Shorter heating times were required to inactivate both trypsin and chymotrypsin inhibitor activity in LTI compared to control soybeans. The use of LTI may increase the economic viability of soybeans as protein supplements for humans.