Characterization of trypsin-like enzymes from human saliva isolated by use of affinity chromatography

Paraffin-stimulated whole mixed saliva was collected from 6 individuals and pooled. Three trypsin-like enzymes from saliva supernatant and two from the saliva sediment were isolated by use of affinity chromatography on a soybean trypsin inhibitor Sepharose 4 B column. The isoelectric points for these enzymes were pI 8.0, 6.8 and 6.4 from the supernatant and 6.4 and 6.2 from the sediment. The enzymes were characterized with respect to pH-optimum, pH-stability, temperature stability, substrate specificity and influence of metal ions and inhibitors. The Michaelis constants were determined for these enzymes on the substrates BAEE and TAME.