Isovaleryl-CoA dehydrogenase

In enzymology, an isovaleryl-CoA dehydrogenase (EC 1.3.8.4) is an enzyme that catalyzes the chemical reaction

3-methylbutanoyl-CoA + acceptor ${\displaystyle \rightleftharpoons }$ 3-methylbut-2-enoyl-CoA + reduced acceptor

isovaleryl-CoA dehydrogenase
Isovaleryl-CoA dehydrogenase tetramer, Human
Identifiers
EC no.	1.3.8.4
CAS no.	37274-61-6
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

Thus, the two substrates of this enzyme are 3-methylbutanoyl-CoA and acceptor, whereas its two products are 3-methylbut-2-enoyl-CoA and reduced acceptor.

This enzyme belongs to the family of oxidoreductases, specifically those acting on the CH-CH group of donor with other acceptors. The systematic name of this enzyme class is 3-methylbutanoyl-CoA:acceptor oxidoreductase. Other names in common use include isovaleryl-coenzyme A dehydrogenase, isovaleroyl-coenzyme A dehydrogenase, and 3-methylbutanoyl-CoA:(acceptor) oxidoreductase. This enzyme participates in valine, leucine and isoleucine degradation. It employs one cofactor, FAD.

Structural studies

As of late 2007, only one structure has been solved for this class of enzymes, with the PDB accession code 1IVH. It was created by a group containing K.A.Tiffany, D.L.Roberts, M.Wang, R.Paschke, A.-W.A.Mohsen, J.Vockley, and J.J.P.Kim. The structure was released on May 20, 1998.Doe. "PDBsum entry: 1ivh". Retrieved November 25, 2019.

Leucine metabolism

Leucine metabolism in humans L-Leucine Branched-chain amino acid aminotransferase α-Ketoglutarate Glutamate Glutamate Alanine Pyruvate Muscle: α-Ketoisocaproate (α-KIC) Liver: α-Ketoisocaproate (α-KIC) Branched-chain α-ketoacid dehydrogenase (mitochondria) KIC-dioxygenase (cytosol) Isovaleryl-CoA β-Hydroxy β-methylbutyrate (HMB) Excreted in urine (10–40%) HMB-CoA β-Hydroxy β-methylglutaryl-CoA (HMG-CoA) β-Methylcrotonyl-CoA (MC-CoA) β-Methylglutaconyl-CoA (MG-CoA) CO2 CO2 O2 CO2 H2O CO2 H2O (liver) HMG-CoA lyase Enoyl-CoA hydratase Isovaleryl-CoA dehydrogenase MC-CoA carboxylase MG-CoA hydratase HMG-CoA reductase HMG-CoA  synthase β-Hydroxybutyrate dehydrogenase Mevalonate pathway Thiolase Unknown enzyme β-Hydroxybutyrate Acetoacetyl-CoA Acetyl-CoA Acetoacetate Mevalonate Cholesterol Human metabolic pathway for HMB and isovaleryl-CoA relative to L-leucine.[1][2][3] Of the two major pathways, L-leucine is mostly metabolized into isovaleryl-CoA, while only about 5% is metabolized into HMB.[1][2][3]