Hydrolysis of chromogenic substrates and tame by the mixture of α2macroglobulin and trypsin

Abstract

When trypsin was added to plasma, hydrolysis of fluorescamine-labeled casein (f-casein) was inhibited, but hydrolysis of TAMe (tosyl arginine methyl ester) was rather enhanced. The hydrolysis of f-casein by the mixture of α 2M and trypsin was inhibited, however a slight, but still significant extent of hydrolysis was observed. The hydrolysis of TAMe by α 2M and trypsin was higher than trypsin itself, but that of S-2222 by α 2M-trypsin complex was less than trypsin itself. Comparison of the extent of hydrolysis of various substrates by α 2M-trypsin complex shows that some substrates (S-2222, S-2444, S-2160, S-2238) were less hydrolyzed by α 2M-trypsin complex than by trypsin, but some substrates (TAMe, S-2251) were more hydrolyzed. The extent of hydrolysis of various substrates by α 2M-trypsin complex was not merely determined by molecular weights of these substrates, nor sensitivity of these substrates to trypsin.