[Purification and properties of inhibitor from vegetative portion of alfalfa].

Trypsin inhibitor was isolated from the vegetative portion of alfalfa and purified 270-fold by affinity chromatography on Trypsin-Sepharose. The inhibitor was eluted by gel-filtration as a single peak with molecular weight of 6900. Disc-electrophoresis of the purified inhibitor revealed the presence of only one protein band. Trypsin inhibition is a mixed process. The trypsin inhibitor from alfalfa does not prevent the activity of cathepsin D from bovine brain. Trypsin inhibitor was immobilized on BrCN-activated Sepharose 4B. The binding of trypsin to the immobilized trypsin inhibitor was studied: 5 mg of the immobilized trypsin inhibitor were found to bind 1 mg of trypsin.