title: Differential inhibitory properties of dog and human alpha 1-proteinase inhibitors.
abstract: Dog alpha 1-proteinase inhibitor (alpha 1-PI) was found to be an effective inhibitor of bovine chymotrypsin and also of porcine pancreatic elastase as in the case of human inhibitor. The dog inhibitor inactivated both proteinases at a molar ratio of 1:1. However, compared to the human inhibitor, dog alpha 1-PI was a relatively poor inhibitor of bovine trypsin. The association rate constants (kass) of the interactions of dog alpha 1-PI with bovine chymotrypsin and with porcine elastase were determined to be 6.9 +/- 0.3 X 10(6) M-1 s-1 and 6.4 +/- 0.1 X 10(5) M-1 s-1, respectively. These values are 1.3- and 2.7-fold higher than the corresponding values for the human inhibitor. On the other hand, kass for the dog inhibitor with bovine trypsin (2.6 +/- 0.3 X 10(4)M-1 s-1) was found to be about 5 times smaller than that of the human inhibitor.
mesh_terms: D000595:Amino Acid Sequence; D000818:Animals; D001798:Blood Proteins / Q000494:pharmacology*; D002417:Cattle; D002918:Chymotrypsin / Q000037:antagonists & inhibitors; D004285:Dogs; D006801:Humans; D007700:Kinetics; D010196:Pancreatic Elastase / Q000037:antagonists & inhibitors; D011480:Protease Inhibitors / Q000494:pharmacology*; D013045:Species Specificity; D013379:Substrate Specificity; D013552:Swine; D014357:Trypsin / Q000378:metabolism; D000515:alpha 1-Antitrypsin
chemical_list: D001798:Blood Proteins; D011480:Protease Inhibitors; D000515:alpha 1-Antitrypsin; D002918:Chymotrypsin; D010196:Pancreatic Elastase; D014357:Trypsin