In enzymology, 2-oxoisovalerate dehydrogenase (acylating) () is an enzyme that catalyzes the chemical reaction
The three substrates of this enzyme are ñ-ketoisovaleric acid, coenzyme A (CoA), and oxidised nicotinamide adenine dinucleotide (NAD<sup>+</sup>). Its products are isobutyryl-CoA, carbon dioxide, reduced NADH and a proton.
This enzyme belongs to the family of oxidoreductases, specifically those acting on the aldehyde or oxo group of donor with NAD+ or NADP+ as acceptor. The systematic name of this enzyme class is 3-methyl-2-oxobutanoate:NAD+ 2-oxidoreductase (CoA-methyl-propanoylating). Other names in common use include 2-oxoisovalerate dehydrogenase, and alpha-ketoisovalerate dehydrogenase. This enzyme participates in valine, leucine and isoleucine degradation.