PROPERTIES AND CLASSIFICATION OF THE SOLUBLE ESTERASES OF HUMAN SKELETAL AND SMOOTH MUSCLE

Abstract

Water-soluble proteins and enzymes of human skeletal and smooth muscle were separated by vertical-zone electrophoresis in starch gel and compared with those of human liver and kidney. Thirteen bands of proteins were detected with amido black in skeletal muscle, five of which were also detected in smooth muscle. Various substrates and inhibitors were used in efforts to identify enzymes. Ten bands of esterase activity were detected in skeletal muscle, and nine in smooth muscle. One zone, characteristic of serum cholinesterase, was believed to be due to serum contained in the tissue. A zone of isozymic esterases found in skeletal and smooth muscle was similar to a zone in human liver and kidney and reacted like an acetylesterase. Other esterase bands, which showed a marked hydrolysis of α-naphthyl butyrate, were similar to aliesterases of renal tissue. Observations on alkaline phosphatase, acid phosphatase, aminopeptidase, lactate dehydrogenase, and catalase were recorded for comparison with the data on esterases.