Abstract
The rat submaxillary gland kallikrein (RSGK)(EC 3.4.21.35) was further evaluated. The enzyme was purified to a homogeneous state following the combination of ion exchange chromatographies and gel filtrations. The final kallikrein preparation had a specific activity of 20.4 μmol/min/A280 for N-a-tosyl-L-arginine methyl ester (Tos-Arg-Me) and 132 kallikrein unit (KU) /A280 in a vasodilatation assay, representing a 140 fold purification with an overall yield of 25% of Tos-Arg-Me esterolytic activity from the initial extract. The molecular weight of present enzyme was estimated to be 3.8×104 daltons by Sephadex G-100 gel filtration and SDS gel electrophoresis. The optimum pH for Tos-Arg-Me esterolysis was between 8.5 to 9.5. The RSGK had the esterolytic and amidolytic activities showing wide response profiles against the substrates of synthetic arginine and lysine derivatives. It was found that the N-α-benzoyl-L-arginine methyl ester (Bz-Arg-Me) was most effective one for the RSGK, in the examined. Among the various proteinase inhibitors tested, aprotinin was most inhibitory, while α1-antitrypsin and antithrombin III was less.
