Substrate specificity analysis and inhibitor design of homoisocitrate dehydrogenase.
Homoisocitrate dehydrogenase is involved in the alpha-aminoadipate pathway of biosynthesis of l-lysine in fungi, yeast, some prokaryotic bacteria, and archaea. This enzyme catalyzes the oxidative decarboxylation of (2R,3S)-homoisocitrate into 2-oxoadipate using NAD(+) as a coenzyme. Substrate specificity of two homoisocitrate dehydrogenases derived from Deinococcus radiodurans and Saccharomyces cerevisiae was analyzed using a series of synthetic substrate analogs, which indicated a relatively broad substrate specificity of these enzymes. Based on the substrate specificity, 3-hydroxyalkylidene- and 3-carboxyalkylidenemalate derivatives were designed as a specific inhibitor for homoisocitrate dehydrogenase. The synthetic inhibitors showed a moderate competitive inhibitory activity and (R,Z)-3-carboxypropylidenemalate was the most inhibitory among the synthesized inhibitors. Therefore, homoisocitrate dehydrogenase appeared to recognize preferentially an extended conformation of homoisocitrate.
Yamamoto
Takashi
T
Department of Chemistry and Materials Science, Tokyo Institute of Technology, O-okayama, Meguro-ku, Tokyo 152-8551, Japan.
Miyazaki
Kentaro
K
Eguchi
Tadashi
T
D000429:Alcohol Oxidoreductases / Q000037:antagonists & inhibitors*; D000466:Alkadienes / Q000378:metabolism*; D034301:Deinococcus / Q000201:enzymology*; D015195:Drug Design; D004791:Enzyme Inhibitors / Q000138:chemical synthesis / Q000737:chemistry / Q000494:pharmacology*; D012441:Saccharomyces cerevisiae / Q000201:enzymology*; D013379:Substrate Specificity; D014233:Tricarboxylic Acids / Q000378:metabolism*
D000466:Alkadienes; D004791:Enzyme Inhibitors; D014233:Tricarboxylic Acids; C517550:homoisocitric acid; D000429:Alcohol Oxidoreductases; C021368:homoisocitrate dehydrogenase