Valine N-monooxygenase (, CYP79D1, CYP79D2) is an enzyme with systematic name L-valine,NADPH:oxygen oxidoreductase (N-hydroxylating).This enzyme catalyses the following sequence of chemical reactions:
The enzyme uses molecular oxygen and reduced nicotinamide adenine dinucleotide phosphate (NADPH) to convert L-valine first to its N-hydroxy derivative and then to N,N-dihydroxy-L-valine. This compound is unstable and loses carbon dioxide and water to give the (E) isomer of 2-methylpropanal oxime.
Valine N-monooxygenase is a cytochrome P450 protein containing heme. The product oxime is an intermediate in the biosynthesis of linamarin in Lotus japonicus.