Canine pancreatic kallikrein: enzyme isolation and characterization.

Two forms of canine pancreatic kallikrein, designated as canine pancreatic kallikrein A and B, were separately isolated by ion-exchange, affinity and hydrophobic chromatographies. These enzymes had similar apparent molecular masses, substrate specificities and pH optima. However, kallikrein B was inhibited by soybean trypsin inhibitor, while kallikrein A was not. Both kallikrein A and B were shown by sodium dodecyl sulfate-polyacryl amide gel electrophoresis to consist of two polypeptide chains, designated alpha and beta chains, and binding by disulfide bond(s). The N-terminal amino acid sequences of each alpha and beta chains of kallikrein A and B were determined.