title: Chemical synthesis and in vitro biological evaluation of a phosphorylated bisubstrate inhibitor of type 3 17beta-hydroxysteroid dehydrogenase.
abstract: Type 3 17beta-hydroxysteroid dehydrogenase (17beta-HSD) catalyzes the last step in the biosynthesis of the potent androgen testosterone (T) by selectively reducing the C17 ketone of 4-androstene-3,17-dione (delta4-dione), with NADPH as cofactor. This enzyme is thus an interesting therapeutic target for androgen-sensitive diseases. Using an efficient convergent chemical approach we synthesized a phosphorylated version of the best delta4-dione/adenosine hybrid inhibitor of type 3 17beta-HSD previously reported. An appropriately protected C2' phosphorylated adenosine was first prepared and linked by esterification to the steroid delta4-dione bearing an alkyl spacer. After three deprotection steps, the phosphorylated bisubstrate inhibitor was obtained. The inhibitory potency of this compound was evaluated on homogenated HEK-293 cells overexpressing type 3 17beta-HSD and compared to the best non-phosphorylated bisubstrate inhibitor. Unexpectedly, the phosphorylated derivative was slightly less potent than the non-phosphorylated bisubstrate inhibitor of type 3 17beta-HSD. Two hypotheses are discussed to explain this result: 1) the phosphorylated adenosine moiety does not interact optimally with the cofactor-binding site and 2) the bisubstrate inhibitors, phosphorylated or not, interact only with the substrate-binding site of type 3 17beta-HSD.
authors.affiliation: Medicinal Chemistry Division, Oncology and Molecular Endocrinology Research Center, CHUQ-Pavillon CHUL and Université Laval, Québec G1V 4G2, Canada.
authors.forename: Marie
authors.initials: M
authors.lastname: Bérubé
authors.forename: Donald
authors.initials: D
authors.lastname: Poirier
mesh_terms: D015067:17-Hydroxysteroid Dehydrogenases / Q000037:antagonists & inhibitors*; D000241:Adenosine / Q000031:analogs & derivatives* / Q000138:chemical synthesis / Q000737:chemistry / Q000494:pharmacology; D000735:Androstenedione / Q000031:analogs & derivatives* / Q000138:chemical synthesis / Q000737:chemistry / Q000494:pharmacology; D004791:Enzyme Inhibitors / Q000138:chemical synthesis / Q000737:chemistry / Q000494:pharmacology*; D010766:Phosphorylation; D013379:Substrate Specificity
chemical_list: C520970:5'-O-(11-androst-4'-en-3',17'-dioxo-16'-yl)dodecanoyl-2'-O-phosphate-adenosine; C520969:5'-O-(11-androst-4'-en-3',17'-dioxo-16'-yl)dodecanoyladenosine; D004791:Enzyme Inhibitors; D000735:Androstenedione; D015067:17-Hydroxysteroid Dehydrogenases; C476565:17beta-hydroxysteroid dehydrogenase type 3; D000241:Adenosine