Glycosylated nature of testosterone 5 alpha-reductase 2 purified from human prostate

5 alpha-reductase 2 from human prostate solubilized into an active and stable form using a non-ionic detergent octyl glucoside was successfully purified using a four-step chromatographic procedure. The enzyme was obtained as an apparently homogeneous protein exhibiting an apparent molecular weight of 42 kDa upon SDS-PAGE. Con A, DBA, UEA-I, and RCA60 lectins recognized this protein. After treatment with O-glycosidase and neuraminidase, a protein of an apparent molecular weight about 30 kDa appeared. On the other hand, N-glycosidase treatment of this enzyme had no effect. These results indicate that the human prostate testosterone 5 alpha-reductase 2 is an O-glycosylated sialoglycoprotein with a peptide moiety of about 30 kDa; the oligosaccharide side chains contain mannose, N-acetyl galactosamine, fucose, galactose and sialic acids.