title: NAD(P)+ analogues: tools for the investigation of the active site of oestradiol 17beta-dehydrogenase from human placenta.
abstract: Oestradiol-17beta:NAD+ 17-oxidoreductase from human placenta can accept coenzyme analogues of NAD+ and NADP+ where the amide group is replaced by methyl ketone, nitrile or thioamide. The inhibition with analogues of NAD+ has been studied. The presence of a substituent at C-3 of the pyridinium ring is necessary for the binding. The inhibition by C-4 methylated analogues is very poor, and the effect of a methyl group at C-5 depends on the substituent at C-3. The 1,4,5,6-tetrahydronicotinamide adenine dinucleotide is a competitive inhibitor. Nicotinamide 8-bromoadenine dinucleotide and nicotinamide 8-thioadenine dinucleotide are efficient hydrogen acceptors.
mesh_terms: D001665:Binding Sites; D004960:Estradiol Dehydrogenases / Q000378:metabolism; D005260:Female; D006801:Humans; D006913:Hydroxysteroid Dehydrogenases; D007700:Kinetics; D008968:Molecular Conformation; D009243:NAD / Q000031:analogs & derivatives*; D009249:NADP / Q000031:analogs & derivatives*; D010920:Placenta / Q000201:enzymology*; D011247:Pregnancy; D011485:Protein Binding; D013329:Structure-Activity Relationship
chemical_list: D009243:NAD; D009249:NADP; D006913:Hydroxysteroid Dehydrogenases; D004960:Estradiol Dehydrogenases