Structural specificity of the allosteric inhibitor of phosphoenolpyruvate carboxylase of Escherichia coli.
The structural specificity of the allosteric inhibitor of phosphoenolpyruvate carboxylas [EC 4.1.1.31] of Escherichia coli W was investigated using native enzyme and photooxidized enzyme which was desensitized to L-aspartate. Inhibitory activity was expressed in terms of the concentration of the compound required for 50% inhibition (I0.5). For the native enzyme, L-aspartate and L-malate were the strongest inhibitors with I0.5 values of about 0.10-0.15 mM among about 20 componds tested. For the photooxidized enzyme, oxaloacetate and L-malate were relatively strong inhibitors wiht I0.5 values of about 11-16 mM. The results obtained suggest that the inhibition of the native enzyme mainly reflects allosteric inhibition.
D000494:Allosteric Regulation; D000495:Allosteric Site; D001224:Aspartic Acid / Q000031:analogs & derivatives* / Q000494:pharmacology*; D002262:Carboxy-Lyases / Q000037:antagonists & inhibitors*; D004926:Escherichia coli / Q000201:enzymology*; D007700:Kinetics; D010071:Oxaloacetates / Q000494:pharmacology; D010728:Phosphoenolpyruvate; D013329:Structure-Activity Relationship
D010071:Oxaloacetates; D001224:Aspartic Acid; D010728:Phosphoenolpyruvate; D002262:Carboxy-Lyases