A simple high-yield procedure for isolation of human urinary kallikreins

Two human urinary kallikreins (fractions A-1 and A-2) were purified to apparently homogeneous forms. The two kallikreins were separated by affinity chromatography using Trasylol (aprotinin) covalently bound to Sepharose. The kallikreins were eluted with a pH gradient (pH 9.5-3.0). Fraction A-1 was eluted between pH 6.2 and 4.2 and fraction A-2 was eluted between pH 4.2 and 3.1. Final purification was obtained by chromatography on Sephacryl SS-200. Antibodies prepared against fraction A-2 were also reactive with fraction A-1; thus it may be possible to measure both by radioimmunoassay using the same antibody preparation.