Properties of an arylalkylamine N-acetyltransferase from the nematode, Ascaridia galli.
1. An arylalkylamine N-acetyltransferase (NAT) of the parasitic nematode, Ascaridia galli was studied using either [14C]serotonin (5-HT) or [14C]octopamine (OA) as substrates and with acetyl-CoA as the donor of the acetate group. 2. The NAT activity towards 5-HT and OA co-eluted from a size-exclusion column and appeared to have an M(r) of around 30,000. The enzyme had apparent Km values of 540 +/- 100 microM (+/- SEM) and 33 +/- 4 microM (+/- SEM) for 5-HT and octopamine, respectively, when assayed in the presence of 1 mM acetyl-CoA. 3. High levels of NAT were found in the gonads of male and female worms and the muscle/body wall. 4. N-acetylation was strongly inhibited by Cu2+ but not by other divalent metal ions and the effect of a number of compounds including biogenic amines, formamidines, hydrazines, and beta-carbolines on the arylalkylamine N-acetyltransferase activity was studied.
Muimo
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Department of Pure and Applied Biology, University of Leeds, U.K.
Isaac
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D000105:Acetyl Coenzyme A / Q000378:metabolism*; D000107:Acetylation; D000578:Amidines / Q000494:pharmacology; D000588:Amines / Q000494:pharmacology; D000818:Animals; D001191:Arylamine N-Acetyltransferase / Q000037:antagonists & inhibitors / Q000737:chemistry / Q000378:metabolism*; D001197:Ascaridia / Q000201:enzymology*; D002413:Cations, Divalent / Q000494:pharmacology; D005260:Female; D006066:Gonads / Q000201:enzymology; D007422:Intestines / Q000201:enzymology; D008297:Male; D008970:Molecular Weight; D009132:Muscles / Q000201:enzymology; D009655:Octopamine / Q000378:metabolism*; D012701:Serotonin / Q000378:metabolism*; D013696:Temperature
D000578:Amidines; D000588:Amines; D002413:Cations, Divalent; D009655:Octopamine; D012701:Serotonin; C077922:formamidine; D000105:Acetyl Coenzyme A; D001191:Arylamine N-Acetyltransferase