Inhibitory Spectrum of Mouse Contrapsin and α-1-Antitrypsin against Mouse Serine Proteases1

Publisher Website
Google Scholar
Abstract
Contrapsin and α-1-antitrypsin have been recently characterized as major protease inhibitors in mouse plasma (Takahara, H. & Sinohara, H. (1982) J. Biol. Chem . 257, 2438–2446). We have studied the effects of the two inhibitors upon various serine proteases prepared from mouse tissues. Trypsin, plasmin and trypsin-like proteases of the submaxillary gland were inhibited by contrapsin but not by α-1-antitrypsin. On the other hand, chymotrypsin, elastase, and thrombin were inactivated by α-1-antitrypsin but not by contrapsin. Thus, their inhibitory spectra did not overlap each other in spite of their broad specificities. The inhibition of trypsin, chymotrypsin, and elastase was rapid and stoichiometric, whereas the inhibition of the other proteases was relatively slow. Contrapsin accounted for almost the total capacities of mouse plasma to inhibit both trypsin and submaxillary gland trypsin-like proteases, whereas α-1-antitrypsin was responsible for nearly all the capacities of plasma to inhibit both chymotrypsin and elastase.