THE ISOLATION AND PURIFICATION OF A TRYPSIN INHIBITOR FROM WHOLEWHEAT FLOUR

Abstract

An impure concentrate of a trypsin inhibitor was prepared from a commercial sample of wholewheat flour by ammonium sulfate precipitation. The impure inhibitor was heat-labile and did not inhibit pepsin or α-chymotrypsin activity. When the crude inhibitor was chromatographed on carboxymethyl cellulose, a single protein peak that was about 20 times more active than the original impure inhibitor preparation was obtained.Uultracentrifugal sedimentation patterns and moving-boundary electrophoresis indicated that the material isolated on the carboxymethyl cellulose was nearly homogeneous. In comparison with other known trypsin inhibitors that have been isolated in nearly pure form, wholewheat trypsin inhibitor appears to have a low specific activity.