[Oxidoreductase activity of an unusual liver estrogen-binding protein in rats]

The possibility that an unusual estrogen-binding protein (UEBP) of rat liver possess the oxidoreductase activity (ORA) has been explored. Estrane, androstane, and pregnane steroid derivates (all together 31) were used as a potential substrates. The expression of ORA was referred to as changes in fluorescence of NAD(P)H, which appearance or disappearance follows the steroid oxidation or reduction in a presence of cofactors and highly purified UEBP preparation. In the set conditions the protein didn't show the ORA. The results achieved confirm the conception on the steromodulin function of UEBP which is realized by reversible interaction of the protein with it's steroidal ligands.