Abstract
Human urinary and pancreatic kallikreins were purified by immunoadsorbent column chromatography. The obtained enzymes each showed a single protein band on sodium dodecyl sulfate (SDS) polyacrylamide gel electrophoresis. The properties of the two kallikreins were compared. By both gel filtration and SDS polyacrylamide gel electrophoresis, the molecular weights of urinary and pancreatic kallikreins were estimated to be 42000±3000 and 55000±3000, respectively. The isoelectric point, pH stability and optimum pH of the two enzymes were very similar, and both enzymes were inhibited by serine protease inhibitors such as diisopropyl fluorophosphate, phenylmethyl sulfonylfluoride, aprotinin and α1-proteinase inhibitor. Both kallikreins were stable up to 56°C for 80 min at pH 8.0. Urinary and pancreatic kallikreins gave a fused precipitin line against anti-human urinary kallikrein antibody or anti-human pancreatic kallikrein antibody. The comparisons of enzymic and immunological properties thus suggested that human glandular kallikreins, at least urinary and pancreatic kallikreins, are very similar.
