Inhibition of porcine elastase by turkey ovomucoid and chicken ovoinhibitor.

Abstract

1 Turkey ovomucoid and chicken ovoinhibitor which have been found to be inhibitors of bovine trypsin and α-chymotrypsin can inhibit the esterolytic activities of porcine elastase. The formation of the complex between the elastase and each inhibitor could be demonstrated by means of electrophoresis at pH 6.9. The complexes are formed in molar ratios of one to one. They are stable and no temporary inhibition could be observed. 2 The complexes of porcine elastase with turkey ovomucoid and chicken ovoinhibitor inhibit bovine trypsin at the same molar ratio as free inhibitors. The complex of tryspin with these inhibitors inhibit elastase as do the free inhibitors. The complex of porcine elastase with turkey ovomucoid does not inhibit bovine chymotrypsin and the complex of chymotrypsin with this inhibitor does not inhibit elastase. The complex of porcine elastase with chicken ovoinhibitor inhibits bovine chymotrypsin but not the alkaline proteinase from Aspergillus sojae. The complex of this inhibitor with bovine chymotrypsin inhibits the porcine elastase while the complex with alkaline proteinase does not. It was concluded, therefore, that turkey ovomucoid has two independent binding sites, one for trypsin and the other for chymotrypsin or elastase and that chicken ovoinhibitor has three independent binding sites, one for trypsin, another for chymotrypsin and a third one for either elastase or alkaline proteinase. 3 The complexes between porcine elastase and turkey ovomucoid or chicken ovoinhibitor are not adsorbed on elastin whereas elastase is. 4 Kunitz soybean and pancreatic trypsin inhibitors, Birk-Bowman soybean trypsin and chymotrypsin inhibitor, groundnut and lima bean trypsin and chymotrypsin inhibitors do not inhibit the esterolytic, proteolytic and elasteolytic activities of porcine elastase, even in weight ratios in excess of 10:1.