Evidence for arylamine N-acetyltransferase in the nematode Anisakis simplex.
N-Acetyltransferase activities with p-aminobenzoic acid and 2-aminofluorene were determined in Anisakis simplex, a nematode found in the intestine of the salt water fish Trichiurus lepturus. The N-acetyltransferase activity was determined using an acetyl CoA recycling assay and high pressure liquid chromatography. The N-acetyltransferase activity from a number of Anisakis simplex whole tissue homogenizations was found to be 2.89 +/- 0.52 nmol/min per mg for 2-aminofluorene and 2.54 +/- 0.45 nmol/min per mg for p-aminobenzoic acid. The K(m) and Vmax values obtained were 1.06 +/- 0.69 mM and 9.34 +/- 1.94 nmol/min per mg for 2-aminofluorene, and 2.25 +/- 0.10 mM and 14.44 +/- 0.7 nmol/min per mg for p-aminobenzoic acid. The optimal pH value for the enzyme activity was pH 8.0 for both substrates tested. The optimal temperature for enzyme activity was 37 degrees C for both substrates. The N-acetyltransferase activity was inhibited by iodoacetamide: at 0.25 mM iodoacetamide, activity was reduced 50% and 1.0 mM iodoacetamide inhibits activity more than 90%. Among a series of divalent cations and salts, Cu2+ and Zn2+ were demonstrated to be the most potent inhibitors. This is the first demonstration of acetyl CoA/arylamine N-acetyltransferase activity in a nematode and extends the number of phyla in which this activity has been found.
Chung
J G
JG
Department of Medicine, China Medical College, Taichung, Taiwan, ROC.
Kuo
H M
HM
Lin
T H
TH
Ho
C C
CC
Lee
J H
JH
Lai
J M
JM
Levy
G N
GN
Weber
W W
WW
D010129:4-Aminobenzoic Acid; D000818:Animals; D017163:Anisakis / Q000201:enzymology*; D001191:Arylamine N-Acetyltransferase / Q000302:isolation & purification / Q000378:metabolism*; D002413:Cations, Divalent / Q000494:pharmacology; D002414:Cations, Monovalent / Q000494:pharmacology; D002845:Chromatography; D002850:Chromatography, Gel; D002852:Chromatography, Ion Exchange; D003600:Cytosol / Q000201:enzymology; D017886:Durapatite; D005399:Fishes / Q000469:parasitology; D005449:Fluorenes; D006863:Hydrogen-Ion Concentration; D007422:Intestines / Q000469:parasitology; D007700:Kinetics; D013379:Substrate Specificity
D002413:Cations, Divalent; D002414:Cations, Monovalent; D005449:Fluorenes; C012177:2-aminofluorene; D017886:Durapatite; D001191:Arylamine N-Acetyltransferase; D010129:4-Aminobenzoic Acid