Occurrence of a trypsin inhibitor in eggplant exocarps

A trypsin inhibitor was extracted from eggplant exocarps with several buffers. The 0.1 M acetate buffer, pH 5.5. extract had the highest specific activity. The crude inhibitor, obtained by heat treatment and salting-out from the acetate buffer extract, contained 4.5% nitrogen and 22.6% hexose. Isoelectrofocusing demonstrated that this crude inhibitor in the eggplant exocarps was composed of at least three forms, one of which differed in its isoelectric point. The form at pH 4.7 had the strongest activity. The molecular weights of these inhibitors were estimated to be between 5,000-10,000 by gel filtration.