Characterization of arylamine N-acetyltransferase in Enterobacter aerogenes.
N-acetyltransferase (NAT) activity was determined by incubation of purified Enterobacter aerogenes enzyme with 2-aminofluorene (2-AF) as the substrate, followed by high pressure liquid chromatography assays. The NAT activity from E. aerogenes was 0.58 +/- 0.08 nmol/min/mg protein for 2-AF. The values of apparent K(m) and Vmax were 0.72 +/- 0.14 mM and 2.45 +/- 0.29 nmol/min/mg protein, respectively, for 2-AF. The optimal pH value for the enzyme activity was 7.5 for the 2-AF tested. The optimal temperature for enzyme activity was 37 degrees C for the 2-AF substrate. The molecular weight of NAT from E. aerogenes was 44.9 kD. Among a series of divalent cations and salts, Zn2+, Ca2+, and Fe2+ were demonstrated to be the most potent protease inhibitors, and only ethylenediaminetetraacetic acid significantly protected the NAT. Iodoacetamide, in contrast to other agents, markedly inhibited NAT.
Tsou
M F
MF
Department of Clinical Medicine, China Medical College Hospital, Taichung, Taiwan, Republic of China.
Chung
J G
JG
Wu
L T
LT
Cheng
K S
KS
Hung
C F
CF
D001191:Arylamine N-Acetyltransferase / Q000737:chemistry / Q000302:isolation & purification / Q000378:metabolism*; D002412:Cations / Q000494:pharmacology; D002851:Chromatography, High Pressure Liquid; D003600:Cytosol / Q000201:enzymology; D004591:Electrophoresis, Polyacrylamide Gel; D005449:Fluorenes / Q000378:metabolism; D006801:Humans; D006863:Hydrogen-Ion Concentration; D007422:Intestines / Q000382:microbiology; D007700:Kinetics; D007711:Klebsiella pneumoniae / Q000201:enzymology* / Q000302:isolation & purification; D011480:Protease Inhibitors / Q000494:pharmacology; D012492:Salts / Q000494:pharmacology; D013696:Temperature
D002412:Cations; D005449:Fluorenes; D011480:Protease Inhibitors; D012492:Salts; C012177:2-aminofluorene; D001191:Arylamine N-Acetyltransferase