Proteinase inhibitors from Vigna unguiculata subsp. cylindrica: II. Inhibitors of subtilisin and trypsin

Abstract

Two subtilisin inhibitors and two trypsin-chymotrypsin inhibitors were purified from seeds of Vigna unguiculata subsp. cylindrica. A third subtilisin inhibitor was partially purified. The subtilisin isoinhibitors were present in very small amounts in the seeds and the degree of purification of the three inhibitors was 20,000- to 48,000-fold. The purified inhibitors were found to be homogeneous on ultracentrifugation and polyacrylamide gel electrophoresis with or without dodecyl sulfate. The subtilisin inhibitors had no action on papain, ficin, chymopapain, bromelain, trypsin, chymotrypsin, or papain and the trypsin-chymotrypsin inhibitors were also inactive with other enzymes.