Nicotinamide adenine dinucleotide (NAD) is a coenzyme central to metabolism. Found in all living cells, NAD is called a dinucleotide because it consists of two nucleotides joined through their phosphate groups. One nucleotide contains an adenine nucleobase and the other nicotinamide. NAD exists in two forms: an oxidized and reduced form, abbreviated as NAD+ and NADH (H for hydrogen), respectively.
The branched-chain α-ketoacid dehydrogenase complex is a multi-subunit complex of enzymes that is found on the mitochondrial inner membrane. This enzyme complex catalyzes the oxidative decarboxylation of branched, short-chain alpha-ketoacids. BCKDC is a member of the mitochondrial α-ketoacid dehydrogenase complex family comprising pyruvate dehydrogenase and alpha-ketoglutarate dehydrogenase, key enzymes that function in the Krebs cycle.
Phosphorylase kinase (PhK) is a serine/threonine-specific protein kinase which activates glycogen phosphorylase to release glucose-1-phosphate from glycogen. PhK phosphorylates glycogen phosphorylase at two serine residues, triggering a conformational shift which favors the more active glycogen phosphorylase “a” form over the less active glycogen phosphorylase b.
Pyruvate dehydrogenase is an enzyme that catalyzes the reaction of pyruvate and a lipoamide to give the acetylated dihydrolipoamide and carbon dioxide. The conversion requires the coenzyme thiamine pyrophosphate.
In enzymology, a 3-hydroxyisobutyrate dehydrogenase also known as β-hydroxyisobutyrate dehydrogenase or 3-hydroxyisobutyrate dehydrogenase, mitochondrial (HIBADH) is an enzyme that in humans is encoded by the HIBADH gene.
Glutathione S-transferase A1 is an enzyme that in humans is encoded by the GSTA1 gene.
5'-AMP-activated protein kinase catalytic subunit alpha-1 is an enzyme that in humans is encoded by the PRKAA1 gene.
Hydroxyprostaglandin dehydrogenase 15-(NAD), also called 15-hydroxyprostaglandin dehydrogenase [NAD+], is an enzyme that in humans is encoded by the HPGD gene.
Tyrosyl-DNA phosphodiesterase 1 is an enzyme that in humans is encoded by the TDP1 gene.
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
NQO2 is a homodimer. NQO2 can be inhibited by resveratrol. One of QR2's binding sites responds to 2-iodomelatonin, and has been referred to as MT3.
MTHFD1 is a gene located in humans on chromosome 14 that encodes for a protein with three distinct enzymatic activities. C-1-tetrahydrofolate synthase, cytoplasmic also known as C1-THF synthase is an enzyme that in humans is encoded by the MTHFD1 gene.
Deoxyhypusine synthase is an enzyme that in humans is encoded by the DHPS gene.
NADP-dependent malic enzyme is a protein that in humans is encoded by the ME1 gene.
NAD(P) transhydrogenase, mitochondrial is an enzyme that in humans is encoded by the NNT gene on chromosome 5.
Sorbitol dehydrogenase is an enzyme that in humans is encoded by the SORD gene.
NAD-dependent deacetylase sirtuin-3, mitochondrial also known as SIRT3 is a protein that in humans is encoded by the SIRT3 gene [sirtuin 3 ]. SIRT3 is member of the mammalian sirtuin family of proteins, which are homologs to the yeast Sir2 protein. SIRT3 exhibits NAD+-dependent deacetylase activity.
Acyl-protein thioesterase 1 is an enzyme that in humans is encoded by the LYPLA1 gene.
Bifunctional methylenetetrahydrofolate dehydrogenase/cyclohydrolase, mitochondrial is an enzyme that in humans is encoded by the MTHFD2 gene.
Sirtuin 4, also known as SIRT4, is a mitochondrial protein which in humans is encoded by the SIRT4 gene. SIRT4 is member of the mammalian sirtuin family of proteins, which are homologs to the yeast Sir2 protein. SIRT4 exhibits NAD+-dependent deacetylase activity.
In molecular biology, the ELFV dehydrogenase family of enzymes include glutamate, leucine, phenylalanine and valine dehydrogenases. These enzymes are structurally and functionally related. They contain a Gly-rich region containing a conserved Lys residue, which has been implicated in the catalytic activity, in each case a reversible oxidative deamination reaction.
