3-Isopropylmalate dehydrogenase

3-Isopropylmalate dehydrogenase (EC 1.1.1.85) is an enzyme that is a part of the isopropylmalate dehydrogenase family, which catalyzes the overall chemical reaction:^[1][2][3][4]

(2R,3S)-3-isopropylmalic acid

+ NAD⁺

 

 

 

H⁺

 

H⁺

 

α-ketoisocaproic acid

+ CO₂ + NADH

 

3-Isopropylmalate dehydrogenase
Identifiers
EC no.	1.1.1.85
CAS no.	9030-97-1
Databases
IntEnz	IntEnz view
BRENDA	BRENDA entry
ExPASy	NiceZyme view
KEGG	KEGG entry
MetaCyc	metabolic pathway
PRIAM	profile
PDB structures	RCSB PDB PDBe PDBsum
Gene Ontology	AmiGO / QuickGO
Search PMC articles PubMed articles NCBI proteins

The first step is an oxidation reaction in which the cofactor, oxidised nicotinamide adenine dinucleotide (NAD⁺), converts the hydroxy group of the malic acid derivative into the corresponding keto group. This spontaneously decarboxylates to give the observed product.^[5]