Esterase-29 (ES-29): biochemical characterization and control by two independent gene loci of a...

Biochemistry and genetics of a testosterone-dependent murine serum esterase designated esterase-29 (ES-29) are described. The enzyme was identified after disc electrophoresis and subsequent staining for esterase using alpha-naphthyl acetate as the substrate. It was inhibited by bis-p-nitrophenyl phosphate and was resistant to p-chlorophenylsulphonate and hence was classified as carboxylesterase EC3.1.1.1. The molecular mass was estimated to be about 130 kDa. It was shown that ES-29 is under the control of two independent genes. The first, termed Es-29, is suggested to be a structural locus, linked to the cluster-2 esterase loci on chromosome 8. Three alleles at Es-29, Es-29a, Es-29b, and Es-29c are distinguished, which determine absence (SEG/1), strong activity (BALB/cJ), and low activity (MOLH/Fre), respectively. The second locus, termed Mse-1 (serum esterase modifying factor), was found to be closely linked to Pre-2 on chromosome 12 and is suggested to be a modifying or regulatory gene. Two alleles were distinguished, Mse-1a (BALB/cJ) and Mse-1m (MOL3/JA, Cas-Bgr), which determine whether ES-29 appears as a single band or a double band, respectively. Mse-1m is dominant to Mse-1a.