酮醇酸还原异构酶

酮醇酸还原异构酶（英语：ketol-acid reductoisomerase，EC 1.1.1.86 （页面存档备份，存于互联网档案馆））是一种以NAD⁺或NADP⁺为受体、作用于供体CH-OH基团上的氧化还原酶。这种酶能催化以下酶促反应：

酮醇酸还原异构酶
命名 系统命名 (R)-2,3-dihydroxy-3-methylbutanoate:NADP+ oxidoreductase (isomerizing) 缩写 KARI 别名 dihydroxyisovalerate dehydrogenase (isomerizing); acetohydroxy acid isomeroreductase; ketol acid reductoisomerase; α-keto-β-hydroxylacyl reductoisomerase; 2-hydroxy-3-keto acid reductoisomerase; acetohydroxy acid reductoisomerase; acetolactate reductoisomerase; dihydroxyisovalerate (isomerizing) dehydrogenase; isomeroreductase; reductoisomerase
识别码
EC编号	1.1.1.86
CAS号	9075-02-9
数据库
IntEnz	IntEnz浏览
BRENDA	BRENDA入口
ExPASy	NiceZyme浏览
KEGG	KEGG入口
MetaCyc	代谢路径
PRIAM	概述
PDB	RCSB PDB PDBj PDBe PDBsum
基因本体	AmiGO / EGO
搜索 PMC 相关文献 PubMed 相关文献

(R)-2,3-二羟基-3-甲基丁酸 + NADP⁺ $\rightleftharpoons$ (S)-2-羟基-2-甲基-3-氧代丁酸 + NADPH + H⁺

酮醇酸还原异构酶还能将2-乙酰-2-羟基丁酸催化转化为2,3-二羟基-3-甲基戊酸。

参考文献

• Arfin SM, Umbarger HE. Purification and properties of the acetohydroxy acid isomeroreductase of Salmonella typhimurium. J. Biol. Chem. 1969, 244 (5): 1118–27. PMID 4388025. 

• Hill RK, Sawada S and Arfin SM. Stereochemistry of valine and isoleucine biosynthesis. IV Synthesis, configuration, and enzymatic specificity of alpha-acetolactate and alpha-aceto-alpha-hydroxybutyrate. Bioorg. Chem. 1979, 8 (2): 175–189. doi:10.1016/0045-2068(79)90003-8. 

• Kiritani K, Narise S and Wagner RP. The reductoisomerase of Neurospora crassa. J. Biol. Chem. 1966, 241: 2047–2051. 

• Satyanarayana T, Radhakrishnan AN. Biosynthesis of valine and isoleucine in plants. 3. Reductoisomerase of Phaseolus radiatus. Biochim. Biophys. Acta. 1965, 110 (2): 380–8. PMID 5866387.