title: The stereochemical course of hydrolysis catalysed by snake venom 5'-nucleotide phosphodiesterase.
abstract: Adenosine 5'-(S)-[16O,17O,18O]phosphate was pyrophosphorylated by the combined action of adenylate kinase and pyruvate kinase. The isotopomers of adenosine 5'-[alpha-16O,17O,18O]triphosphate were hydrolysed by venom 5'-nucleotide phosphodiesterase (Crotalus adamanteus) in H2(17)O. Analysis by 31P nuclear magnetic resonance spectroscopy of the resulting adenosine 5'-[16O,17O,18O]phosphate, after cyclization and esterification, showed that the hydrolysis occurs with retention of configuration at phosphorus. The most likely explanation of this observation is that the enzymic hydrolysis involves a double displacement at phosphorus with a covalent nucleotidyl--enzyme intermediate on the reaction pathway.
mesh_terms: D000249:Adenosine Monophosphate / Q000031:analogs & derivatives / Q000378:metabolism; D000255:Adenosine Triphosphate / Q000378:metabolism; D000818:Animals; D003435:Crotalid Venoms / Q000378:metabolism*; D006868:Hydrolysis; D009682:Magnetic Resonance Spectroscopy; D008968:Molecular Conformation; D043264:Phosphodiesterase I; D010727:Phosphoric Diester Hydrolases / Q000378:metabolism*; D013237:Stereoisomerism; D013873:Thionucleotides / Q000378:metabolism
chemical_list: D003435:Crotalid Venoms; D013873:Thionucleotides; C014308:adenosine 5'-phosphorothioate; D000249:Adenosine Monophosphate; D000255:Adenosine Triphosphate; D010727:Phosphoric Diester Hydrolases; D043264:Phosphodiesterase I; C470790:phosphodiesterase I, snake venom