Purification of kallikrein from cat submaxillary gland

Cat submaxillary kallikrein was purified from the water extract of the gland by 50-75% acetone fractionation, DEAE-Sephadex A-50 chromatography, Sephadex G-75 gel filtration and Ampholine isoelectric focusing. The final preparation gave the activities of 1260 KU/mg in vasodilator assay, 24.5 and 11.6 units/mg on BAEE and TAME esterolytic assay, respectively. Trasylol gave only weak inhibitory effect on this kallikrein. The isoelectric points of the kallikrein were in the range pH 4.2-5.0, and this kallikrein seemed to consist of several multiple forms with different pI values, like some other glandular kallikreins. It gave a single protein band in disc electrophoresis, while it migrated in retard and formed a broad one. This may be ascribable to the rich carbohydrate content in the kallikrein.