胰蛋白酶, TPCK Treated A chromatographically purified, diafiltered, lyophilized powder that has been treated with L-(tosylamido-2-phenyl) ethyl chloromethyl ketone (TPCK) to inhibit contaminating chymotryptic activity [Kostka and Carpenter, J. Biol. Chem. 239, 1799 (1964)].