Kinetic analysis on the substrate specificity of 3‐isopropylmalate dehydrogenase

FEBS Letters

Terasawa, Hiroaki²  Oshima, Tairo¹  Miyazaki, Kentaro¹  Kakinuma, Katsumi² 

[1] Department of Life Science, Tokyo Institute of Technology, Nagatsuta 4259, Midori-ku, Yokohama 227, Japan;Department of Chemistry, Tokyo Institute of Technology, O-okayama, Meguro-ku, Tokyo 152, Japan

关键词: Analog;    Hydrophobicity;    3-Isopropylmalate dehydrogenase;    Substrate specificity;   

DOI  :  10.1016/0014-5793(93)80477-C

学科分类：生物化学/生物物理

来源: John Wiley & Sons Ltd.

【 摘 要 】

Substrate specificity of 3-isopropylmalate dehydrogenase is analyzed using a series of synthetic (2R,3S)-3-alkylmalates. Each analog with hydrogen, methyl, ethyl, isopropyl, isobutyl, tert-butyl, and isoamyl group on C-3 functions as a substrate, implying a broad substrate specificity of the enzyme toward alkylmalates. The incremental binding energy of the isopropyl group of 3-isopropylmalate to the enzyme is estimated to be 3.55 kcal/mol, the rather small value supporting the broad specificity. Although the enzyme shows a broad specificity toward the alkylmalates, it does not show activity with isocitrate which has a negatively charged carboxymethyl group instead of the alkyl groups.

【 授权许可】

Unknown