title: Monkey lactate dehydrogenase-C4 as a model for the interaction of enzymes with gossypol.
abstract: Lactate dehydrogenase-C4 (LDH-C4) plays a central role in the metabolism of spermatogenic and mature sperm cells as well as being an enzyme which is inhibited by gossypol, a male contraceptive. Racemic and (+)-gossypol have equivalent potency as inhibitors of LDH-C4 purified from ejaculated sperm of cynomolgus monkeys. Analogues of gossypol (gossypol-glycine ester Schiff's base, 6,6-dimethoxygossypol and ethyl gossypol) have quantitatively similar inhibitory effects of LDH-C4 activity; apogossypol hexaacetate, however, has no inhibitory effect. Other effective inhibitors of LDH-C4 are antimycin, naphthoquinones and lithocholic acid. LDH-C4 may serve as a model for understanding gossypol binding domains and contraceptive action.
mesh_terms: D000818:Animals; D001665:Binding Sites; D003270:Contraceptive Agents / Q000494:pharmacology; D006072:Gossypol / Q000031:analogs & derivatives / Q000494:pharmacology*; D066298:In Vitro Techniques; D007527:Isoenzymes; D007770:L-Lactate Dehydrogenase / Q000037:antagonists & inhibitors*; D008252:Macaca fascicularis; D008297:Male; D008954:Models, Biological; D013094:Spermatozoa / Q000201:enzymology; D013237:Stereoisomerism
chemical_list: D003270:Contraceptive Agents; D007527:Isoenzymes; D007770:L-Lactate Dehydrogenase; D006072:Gossypol