Pyrroloquinoline quinone (PQQ), also called methoxatin, is a redox cofactor and antioxidant.
In enzymology, a methanol dehydrogenase (MDH) is an enzyme that catalyzes the chemical reaction:
In enzymology, a quinate dehydrogenase (EC 1.1.1.24) is an enzyme that catalyzes the chemical reaction
In enzymology, an alcohol dehydrogenase (acceptor) (EC 1.1.99.8) is an enzyme that catalyzes the chemical reaction
In enzymology, a choline dehydrogenase is an enzyme that catalyzes the chemical reaction
In enzymology, a quinoprotein glucose dehydrogenase is an enzyme that catalyzes the chemical reaction
In enzymology, an aldehyde dehydrogenase (pyrroloquinoline-quinone) (EC 1.2.99.3) is an enzyme that catalyzes the chemical reaction
In enzymology, a ribosyldihydronicotinamide dehydrogenase (quinone) (EC 1.10.99.2) is an enzyme that catalyzes the chemical reaction
In enzymology, a NAD(P)H dehydrogenase (quinone) (EC 1.6.5.2) is an enzyme that catalyzes the chemical reaction
NAD(P)H dehydrogenase [quinone] 1 is an enzyme that in humans is encoded by the NQO1 gene. This protein-coding gene is a member of the NAD(P)H dehydrogenase (quinone) family and encodes a 2-electron reductase (enzyme). This FAD-binding protein forms homodimers and performs two-electron reduction of quinones to hydroquinones and of other redox dyes. It has a preference for short-chain acceptor quinones, such as ubiquinone, benzoquinone, juglone and duroquinone. This gene has an important paralog NQO2. This protein is located in the cytosol.
NAD(P)H dehydrogenase, quinone 2, also known as QR2, is a protein that in humans is encoded by the NQO2 gene. It is a phase II detoxification enzyme which can carry out two or four electron reductions of quinones. Its mechanism of reduction is through a ping-pong mechanism involving its FAD cofactor. Initially in a reductive phase NQO2 binds to reduced dihydronicotinamide riboside (NRH) electron donor, and mediates a hydride transfer from NRH to FAD. Then, in an oxidative phase, NQO2 binds to its quinone substrate and reduces the quinone to a dihydroquinone. Besides the two catalytic FAD, NQO2 also has two zinc ions. It is not clear whether the metal has a catalytic role. NQO2 is a paralog of NQO1.
Quinate/shikimate dehydrogenase (EC 1.1.1.282, YdiB) is an enzyme with systematic name L-quinate:NAD(P)+ 3-oxidoreductase. This enzyme catalyses the following chemical reaction
Alcohol dehydrogenase (cytochrome c) (EC 1.1.2.8, type I quinoprotein alcohol dehydrogenase, quinoprotein ethanol dehydrogenase) is an enzyme with systematic name alcohol:cytochrome c oxidoreductase. This enzyme catalyses the following chemical reaction
Alcohol dehydrogenase (quinone) (EC 1.1.5.5, type III ADH, membrane associated quinohaemoprotein alcohol dehydrogenase) is an enzyme with systematic name alcohol:quinone oxidoreductase. This enzyme catalyses the following chemical reaction
Cyclic alcohol dehydrogenase (quinone) (EC 1.1.5.7, cyclic alcohol dehydrogenase, MCAD) is an enzyme with systematic name cyclic alcohol:quinone oxidoreductase. This enzyme catalyses the following chemical reaction
Alcohol dehydrogenase (azurin) (EC 1.1.9.1, type II quinoprotein alcohol dehydrogenase, quinohaemoprotein ethanol dehydrogenase, QHEDH, ADHIIB) is an enzyme with systematic name alcohol:azurin oxidoreductase. This enzyme catalyses the following chemical reaction
Soluble quinoprotein glucose dehydrogenase is an enzyme with systematic name D-glucose:acceptor oxidoreductase. This enzyme catalyses the following chemical reaction
Fumarate reductase (quinol) (EC 1.3.5.4, QFR,FRD, menaquinol-fumarate oxidoreductase, quinol:fumarate reductase) is an enzyme with systematic name succinate:quinone oxidoreductase. This enzyme catalyzes the following chemical reaction:
NADH:ubiquinone reductase (non-electrogenic) (EC 1.6.5.9, NDH-2, ubiquinone reductase, coenzyme Q reductase, dihydronicotinamide adenine dinucleotide-coenzyme Q reductase, DPNH-coenzyme Q reductase, DPNH-ubiquinone reductase, NADH-coenzyme Q oxidoreductase, NADH-coenzyme Q reductase, NADH-CoQ oxidoreductase, NADH-CoQ reductase) is an enzyme with systematic name NADH:ubiquinone oxidoreductase. This enzyme catalyses the following chemical reaction:
NADH dehydrogenase is an enzyme that converts nicotinamide adenine dinucleotide (NAD) from its reduced form (NADH) to its oxidized form (NAD+). Members of the NADH dehydrogenase family and analogues are commonly systematically named using the format NADH:acceptor oxidoreductase. The chemical reaction these enzymes catalyze is generally represented with the following equation:
