title: S-Adenosylhomocysteine hydrolase activity in Trichomonas vaginalis and other trichomonads.
abstract: S-Adenosylhomocysteine hydrolase has been detected in crude homogenates of Trichomonas vaginalis, Tritrichomonas foetus and Trichomitus batrachorum at activities of 14, 1.2 and 3.3 nmol min-1 mg-1 protein, respectively. The enzyme from T. vaginalis was found to be soluble with pH optimum of 8.0 and apparent Km values for adenosine and homocysteine of 100 and 155 microM, respectively. Ara A was shown to inhibit the T. vaginalis enzyme but only at relatively high concentration (I50 100 microM), whereas sinefungin and 2'-deoxyadenosine had only small inhibitory effects. EDTA (I50 6 mM) and various divalent cations also inhibited the enzyme from T. vaginalis.
mesh_terms: D000241:Adenosine / Q000031:analogs & derivatives / Q000494:pharmacology; D043383:Adenosylhomocysteinase; D000818:Animals; D003839:Deoxyadenosines / Q000494:pharmacology; D004492:Edetic Acid / Q000494:pharmacology; D056890:Eukaryota / Q000201:enzymology*; D006863:Hydrogen-Ion Concentration; D006867:Hydrolases / Q000378:metabolism*; D008099:Liver / Q000201:enzymology; D014246:Trichomonas vaginalis / Q000201:enzymology*; D014318:Tritrichomonas / Q000201:enzymology*; D014740:Vidarabine / Q000494:pharmacology
chemical_list: D003839:Deoxyadenosines; D004492:Edetic Acid; D006867:Hydrolases; D043383:Adenosylhomocysteinase; D014740:Vidarabine; D000241:Adenosine; C006235:sinefungin