Flavin adenine dinucleotide

"FAD" redirects here. For other uses, see FAD (disambiguation).
Flavin adenine dinucleotide
Stereo, Kekulé, skeletal formula of FAD
Spacefill model of FAD
Identifiers
3D model (JSmol)
3DMet
1208946
ChEBI
ChEMBL
DrugBank
ECHA InfoCard 100.005.149 Edit this at Wikidata
EC Number
  • 205-663-1
108834
KEGG
MeSH Flavin-Adenine+Dinucleotide
UNII
  • InChI=1S/C27H33N9O15P2/c1-10-3-12-13(4-11(10)2)35(24-18(32-12)25(42)34-27(43)33-24)5-14(37)19(39)15(38)6-48-52(44,45)51-53(46,47)49-7-16-20(40)21(41)26(50-16)36-9-31-17-22(28)29-8-30-23(17)36/h3-4,8-9,14-16,19-21,26,37-41H,5-7H2,1-2H3,(H,44,45)(H,46,47)(H2,28,29,30)(H,34,42,43)/t14-,15+,16+,19-,20+,21+,26+/m0/s1 checkY[PubChem]
    Key: VWWQXMAJTJZDQX-UYBVJOGSSA-N checkY[PubChem]
  • quinone form: c12cc(C)c(C)cc1N=C3C(=O)NC(=O)N=C3N2C[C@H](O)[C@H](O)[C@H](O)COP(=O)(O)OP(=O)(O)OC[C@@H]4[C@@H](O)[C@@H](O)[C@@H](O4)n5cnc6c5ncnc6N
  • semiquinone form: c12cc(C)c(C)cc1N[C]3C(=O)NC(=O)N=C3N2C[C@H](O)[C@H](O)[C@H](O)COP(=O)([O-])OP(=O)([O-])OC[C@@H]4[C@@H](O)[C@@H](O)[C@@H](O4)n5cnc6c5ncnc6N
  • hydroquinone form: c12cc(C)c(C)cc1NC=3C(=O)NC(=O)NC=3N2C[C@H](O)[C@H](O)[C@H](O)COP(=O)([O-])OP(=O)([O-])OC[C@@H]4[C@@H](O)[C@@H](O)[C@@H](O4)n5cnc6c5ncnc6N
  • flavin-N(5)-oxide form: c12cc(C)c(C)cc1[N+]([O-])=C3C(=O)NC(=O)N=C3N2C[C@H](O)[C@H](O)[C@H](O)COP(=O)(O)OP(=O)(O)OC[C@@H]4[C@@H](O)[C@@H](O)[C@@H](O4)n5cnc6c5ncnc6N
Properties
C27H33N9O15P2
Molar mass 785.557 g·mol−1
Appearance White, vitreous crystals
log P -1.336
Acidity (pKa) 1.128
Basicity (pKb) 12.8689
Except where otherwise noted, data are given for materials in their standard state (at 25 °C [77 °F], 100 kPa).
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In biochemistry, flavin adenine dinucleotide (FAD) is a redox-active coenzyme associated with various proteins, which is involved with several enzymatic reactions in metabolism. A flavoprotein is a protein that contains a flavin group, which may be in the form of FAD or flavin mononucleotide (FMN). Many flavoproteins are known: components of the succinate dehydrogenase complex, α-ketoglutarate dehydrogenase, and a component of the pyruvate dehydrogenase complex.

FAD can exist in four redox states, which are the flavin-N(5)-oxide, quinone, semiquinone, and hydroquinone.[1] FAD is converted between these states by accepting or donating electrons. FAD, in its fully oxidized form, or quinone form, accepts two electrons and two protons to become FADH2 (hydroquinone form). The semiquinone (FADH·) can be formed by either reduction of FAD or oxidation of FADH2 by accepting or donating one electron and one proton, respectively. Some proteins, however, generate and maintain a superoxidized form of the flavin cofactor, the flavin-N(5)-oxide.[2][3]

  1. ^ Teufel, Robin; Agarwal, Vinayak; Moore, Bradley S. (2016-04-01). "Unusual flavoenzyme catalysis in marine bacteria". Current Opinion in Chemical Biology. 31: 31–39. doi:10.1016/j.cbpa.2016.01.001. ISSN 1879-0402. PMC 4870101. PMID 26803009.
  2. ^ Teufel, R; Miyanaga, A; Michaudel, Q; Stull, F; Louie, G; Noel, JP; Baran, PS; Palfey, B; Moore, BS (28 November 2013). "Flavin-mediated dual oxidation controls an enzymatic Favorskii-type rearrangement". Nature. 503 (7477): 552–6. Bibcode:2013Natur.503..552T. doi:10.1038/nature12643. PMC 3844076. PMID 24162851.
  3. ^ Teufel, Robin; Stull, Frederick; Meehan, Michael J.; Michaudel, Quentin; Dorrestein, Pieter C.; Palfey, Bruce; Moore, Bradley S. (2015-07-01). "Biochemical Establishment and Characterization of EncM's Flavin-N5-oxide Cofactor". Journal of the American Chemical Society. 137 (25): 8078–8085. doi:10.1021/jacs.5b03983. ISSN 1520-5126. PMC 4720136. PMID 26067765.