title: omega-haloalkyl esters of 5'-adenosine monophosphate as potential active-site-directed reagents for dehydrogenases.
abstract: A series of esters of adenosine 5'-monophosphate with ethyl, propyl, or hexyl moieties substituted at the omega-position with chlorine or bromine were prepared. The compounds were competitive inhibitors of horse liver alcohol dehydrogenase with respect to coenzyme, NAD+, and had inhibition (dissociation) constants in the range of 40 to 260 microM at pH 8.0, 25 degrees C. The bromoalkyl esters were designed to be active-site-directed inactivators and were chemically reactive as tested with the model compound 4-(p-nitrobenzyl)pyridine. Yeast alcohol dehydrogenase was inactivated by the bromohexyl analog by an active-site-directed mechanism, with a Ki = 1.5 mM and a pseudo-bimolecular rate constant of 0.03 M-1 S-1, which is 150 times larger than the bimolecular rate constant for inactivation by 2-bromoethanol. However, the rates of inactivation of other dehydrogenases treated with 10 mM concentrations of these compounds were generally slower than with the simpler reagent, 2-bromoethanol. Thus, the reactive functional group attached to the AMP moiety may not be properly oriented for affinity labeling of these dehydrogenases. The bromoalkyl esters may be useful for inactivating other enzymes.
mesh_terms: D000249:Adenosine Monophosphate / Q000031:analogs & derivatives* / Q000494:pharmacology; D000429:Alcohol Oxidoreductases / Q000037:antagonists & inhibitors; D000818:Animals; D001665:Binding Sites / Q000187:drug effects; D001667:Binding, Competitive; D002417:Cattle; D004952:Esters / Q000494:pharmacology; D006219:Halogens / Q000494:pharmacology; D006736:Horses; D007202:Indicators and Reagents; D008099:Liver / Q000201:enzymology; D010088:Oxidoreductases / Q000037:antagonists & inhibitors*; D011817:Rabbits; D012441:Saccharomyces cerevisiae; D013329:Structure-Activity Relationship; D013552:Swine
chemical_list: D004952:Esters; D006219:Halogens; D007202:Indicators and Reagents; D000249:Adenosine Monophosphate; D010088:Oxidoreductases; D000429:Alcohol Oxidoreductases