Preliminary characterization of a Kazal-type serine protease inhibitor from Caiman crocodilus yacare plasma

Blood serine protease inhibitors are becoming better understood and increas ingly applied in blood clotting, cancer and other diseases. Reptiles are su itable models for blood coagulation and related processes, moreover, caiman is a good comparative model of a non-poisonous reptile. Recently, we repor ted the purification of a kininogen, the presence of proteases involved in blood clotting, and a serine protease inhibitor in Caiman crocodilus yacare plasma. In this paper, we described the partial sequence of an inhibitor ( CcTI). The inhibitor is an 80-kDa protein, and it inactivates trypsin and c hymotrypsin the hydrolysis of specific chromogenic substrates and in the de gradation of gelatin. The inhibitor is member of Kazal-type inhibitor famil y and consists of several domains, its putative reactive: site is Arg-His. (C) 1999 Elsevier Science B.V. All rights reserved.