NAD(P)H dehydrogenase (quinone 1)
This FAD-binding protein forms homodimers and performs two-electron reduction of quinones to hydroquinones and of other redox dyes.[11] Quinonoid compounds generate reactive oxygen species (ROS) via redox cycling mechanisms and arylating nucleophiles.The localization of NQO1 in epithelial and endothelial tissues of mice, rats and humans indicates their importance in detoxifying agent, since their location facilitates exposure to compounds entering the body.The enzyme is also involved in biosynthetic processes such as the vitamin K-dependent gamma-carboxylation of glutamate residues in prothrombin synthesis.[17] Recent pharmacological research suggests feasibility of genotype-directed redox chemotherapeutic intervention targeting NQO1*2 breast cancer.[19] One further single nucleotide polymorphism, found homozygous in 0% to 5% of different ethnic population, is leading to an amino acid exchange on position 139 from arginine to tryptophane.Mutations in this gene have been associated with tardive dyskinesia (TD), an increased risk of hematotoxicity after exposure to benzene, and susceptibility to various forms of cancer.[11] A case-control study conducted in China showed that patients with two copies of the NQO1 C609T (NQO1*2 polymorphism) mutation had a 7.6-fold increased risk of benzene poisoning compared to those who carried one or two wild-type NQO1 alleles.English, Japanese: No significant change This article incorporates text from the United States National Library of Medicine, which is in the public domain.