title: The conformation of adenosine diphosphoribose and 8-bromoadenosine diphosphoribose when bound to liver alcohol dehydrogenase.
abstract: 8-Bromo-adenosine diphosphoribose (br8 ADP-Rib) and nicotinamide 8-bromoadenine dinucleotide (Nbr8AD+) which are analogues of the coenzyme NAD+, were prepared and their liver alcohol dehydrogenase complexes studied by crystallographic methods. Nbr8AD+ is active in alcohol dehydrogenase complexes studied by crystallographic methods. Nbr8AD+ is active in hydrogen transport and br8ADP-Rib is a coenzyme competitive inhibitor for the enzymes liver alcohol dehydrogenase and yeast alcohol dehydrogenase. X-ray data were obtained for the complex between liver alcohol dehydrogenase and br8ADP-Rib to 0.45 nm resolution and for the liver alcohol dehydrogenase-adenosine diphosphoribose complex to 0.29-nm resolution. The conformations of these analogues were determined from the X-ray data. It was found that ADP-Rib had a conformation very similar to the corresponding part of NAD+, when NAD+ is bound to lactate and malate dehydrogenase. br8ADP-Rib had the same anti conformation of the adenine ring with respect to the ribose as ADP-Rib and NAD+, in contrast to the syn conformation found in 8-bromo-adenosine. The overcrowding at the 8-position is relieved in br8ADP-Rib by having the ribose in the 2' endo condormation instead of the usual 3' endo as in ADP-Rib and NAD+.
mesh_terms: D000429:Alcohol Oxidoreductases / Q000378:metabolism*; D001667:Binding, Competitive; D001966:Bromine; D003461:Crystallography; D007527:Isoenzymes; D007700:Kinetics; D008099:Liver / Q000201:enzymology; D009682:Magnetic Resonance Spectroscopy; D008968:Molecular Conformation; D009243:NAD / Q000031:analogs & derivatives*; D009702:Nucleoside Diphosphate Sugars; D011485:Protein Binding; D012441:Saccharomyces cerevisiae / Q000201:enzymology; D014961:X-Ray Diffraction
chemical_list: D007527:Isoenzymes; D009702:Nucleoside Diphosphate Sugars; D009243:NAD; D000429:Alcohol Oxidoreductases; D001966:Bromine