Association of human alpha1-antitrypsin with anhydrotrypsin

Unlike in the reaction of anhydrotrypsin and soybean trypsin inhibitor, human alpha1-antitrypsin was found not to form a complex with bovine anhydrotrypsin. This was shown using three different methods: electrophoresis, affinity chromatography on an anhydrotrypsin-coupled Sepharose column and equilibrium competitive binding assay. These results indicate the importance of the active site serine of trypsin in formation of a complex with alpha1-antitrypsin.