Human skin proteases.

Abstract

A stepwise extraction with different concentrations of KCl in buffer revealed marked differences in the extractability of numerous human skin proteases. Enzymes hydrolyzing casein optimally at pH 5.8, hemoglobin at pH 3.5–5.0, tyrosine ethyl ester (TEE) at pH 7.7 and benzoyl arginine naphthylamide (BANA) at pH 5.8 were extracted almost entirely in a dilute buffer, while a high salt concentration of KCl was required for optimal extraction of the others, e.g. 1 mol/l for enzymes hydrolyzing benzoyl arginine ethyl ester (BAEE), tosyl arginine methyl ester (TAME) and benzoyl arginine p-nitroanilide (BAPA) and 1.5 mol/l for enzymes hydrolyzing acetyl tyrosine ethyl ester (ATEE) and casein optimally at pH 7.8–8.2. The 1.07 mol/l KCl extract of the buffer extracted homogenate hydrolyzed much more effectively casein and ATEE around pH 8.0 than the extract made directly in 1.07 mol/l KCl. The reverse was true in the hydrolysis of the arginine substrates for trypsin-like enzymes, i.e. BAEE, TAME and BAPA.