Proteolytic enzymes and biological inhibitors. VI. Antibodies in animal sera against the proteinase of Corynebacterium pyogenes.

It was demonstrated with the aid of the casein precipitating inhibition test (CPI-test) that chicken egg white, colostrum from different animal species, and extracts of grain and potato, contained inhibitory substances against trypsin, α-chymotrypsin, a number of microbial proteinases, and ficin and papain. Extracts of Ascaris suum contained inhibitory substances which were active against the animal, and several of the microbial proteinases tested, but not against ficin and papain. A semiquantitative measure for the inhibitory capacity of chicken egg white, different colostrum species, extracts of wheat, barley, rye, and corn flours, and extracts of potato upon various enzymes, is given. By combination of paper electrophoresis of the inhibitor-containing materials with the CPI-test (electrophoretic CPI-test), it was found that each of the materials investigated contained several electrophoretically distinguishable inhibitors, with different inhibitory spectra. Some of these inhibitors were active against one single enzyme of animal or microbial origin, others seemed to be active against two enzymes, such as trypsin and α-chymotrypsin, proteinases from Bacillus subtilis and Aspergillus oryzae, or ficin and papain, while still others affected a variety of different enzymes. Some inhibitors seemed to affect swine trypsin but not bovine trypsin. Of the two enzyme fractions in the crude Aspergillus oryzae proteinase, only one was affected by many of the inhibitory substances. The number of inhibitors, as well as the pattern of the different inhibitors in colostrum from different individuals of the same species, seemed also to differ. Many of the inhibitors demonstrated have not been reported previously.