Biochemical characterization of a low trypsin inhibitor soybean

A low trypsin inhibitor soyabean (LTI) was characterized using electrophoresis, enzyme activity measurements and gel exclusion chromatography. The protein profiles were similar to a control soyabean. 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 a 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 with control soyabeans. The use of LTI may increase the economic viability of soyabeans as protein supplements for man..