Characterization of kallikrein from human saliva isolated by use of affinity chromatography

Abstract

Kallikrein was isolated from paraffin stimulated saliva by use of two steps affinity chromatography. A 610-fold purification of the enzyme was achieved by use of Sepharose 4B conjugated with soy bean trypsin inhibitor and pancreatic trypsin inhibitor. The isoelectric point of kallikrein was found to be pH 4.3 and the molecular weight was calculated to be about 38.000 by gel filtration on a AcA 44 Ultrogel column. The enzyme had a pH optimum at pH 8.6 using BAEE and TAME as substrates. The michaelis constant for kallikrein on these two substrates was 4.0. 10⁻⁴M and 5.5. 10⁻⁴M. respectively.