Cloning, expression and functional characterization of type 1 and type 2 steroid 5α-reductases from Cynomolgus monkey : comparisons with human and rat isoenzymes

摘要: Abstract The Cynomolgus monkey may provide an alternative pharmacological model in which to evaluate the efficacy of novel inhibitors two known human steroid 5α-reductase (SR) isoenzymes. To suitability this species at level molecular targets, a prostate cDNA library was prepared and screened using SR type 1 2 cDNAs as hybridization probes. Two distinct sequences were isolated encoding These share 93 95% amino acid sequence identity with their enzyme counterparts, respectively. Difference SR, however, found within contiguous four acids corresponding regions rat that have been proposed previously influence inhibitor affinities. Subsequently, both individually expressed mammalian cell (CHO) line. Enzyme activities SRs localized membrane fractions CHO extracts. Like enzymes, most active neutral low pH, results inhibition studies over 30 inhibitors, including epristeride, 4MA, finasteride, indicate isoenzymes are functionally more similar than homologues. from initial velocity functions pH also compare favorably. results, together, suggest structurally comparable on respective supporting relevance use for vivo evaluation inhibitors.