Isozymes of ribonuclease in human serum and urine. I. Methodology and a survey of a control population.

Methods are presented for the electrophoretic analysis of ribonuclease (RNase) enzymes in human serum and urine. Protocols for sample treatment, electrophoresis, and the RNase zymogram technique are described. With the application of these methods, RNase from serum and urine was separated into components differing on the basis of charge (charge isomers or "isozymes"), but not differing with respect to hydrolyzable sialic acid residues. Preliminary characterization of the electrophoretically separated components showed that some of the RNase species have different properties (pH optima and substrate preference). The major urine RNase isozymes appeared to be distinct from the major serum RNase isozymes. A survey of a control population indicated that the major serum and urine RNase enzymes are not genetically polymorphic.