Study of alternative substrates in the catalytic reaction of N-acetyl-transferase.
In the enzymatic acetylation of para-nitroaniline the esters of para-amino-benzoic acid act as inhibitors since they serve as alternative acceptor substrates. The extent of inhibition is increased by increasing the number of carbon atoms of the alcohol moiety of the esters. The apparent Km value of esters as acceptor substrates decreases by almost one order of magnitude from 1.1 times 10- minus 4 to 2.5 times 10- minus 5 M within the methylester-butylester series. It has been shown by kinetic analyses that the esters are non-competitive inhibitors in respect of the acetyl donor, whereas they are competitive inhibitors in respect of the acetyl acceptor, in the acetylation reaction of paranitroaniline.
D000123:Acetyltransferases / Q000378:metabolism*; D062365:Aminobenzoates; D000818:Animals; D010856:Columbidae; D007700:Kinetics; D008099:Liver / Q000201:enzymology; D013329:Structure-Activity Relationship
D062365:Aminobenzoates; D000123:Acetyltransferases