title: Inhibition of equine S-adenohomocysteine hydrolase by 2'-deoxyadenosine.
abstract: 2'-Deoxyadenosine and 9-beta-D-arabinofuranosyladenine (ARA) are apparent suicide inhibitors for equine S-adenosylhomocysteine hydrolase. In initial velocity studies of the synthetic reaction converting adenosine and homocysteine to S-adenosylhomocysteine, adenine, adenosine 5'-triphosphate, and 9-beta-D-arabinofuranosyladenine were found to be competitive inhibitors with Kis of 3.8 microM, 1.1 mM, and 30 microM, respectively. In contrast, linear mixed inhibition was observed for 2'-deoxyadenosine, indicating that 2'-deoxyadenosine must bind in more than one fashion to the enzyme.
mesh_terms: D000225:Adenine / Q000494:pharmacology; D000241:Adenosine / Q000378:metabolism; D043383:Adenosylhomocysteinase; D000818:Animals; D003839:Deoxyadenosines / Q000494:pharmacology*; D006736:Horses; D006867:Hydrolases / Q000037:antagonists & inhibitors* / Q000096:biosynthesis; D008099:Liver / Q000187:drug effects / Q000201:enzymology* / Q000378:metabolism; D012435:S-Adenosylhomocysteine / Q000096:biosynthesis; D014740:Vidarabine / Q000494:pharmacology
chemical_list: D003839:Deoxyadenosines; D012435:S-Adenosylhomocysteine; D006867:Hydrolases; D043383:Adenosylhomocysteinase; D014740:Vidarabine; D000225:Adenine; D000241:Adenosine