A report on Flavin adenine dinucleotide and Flavin group

Reaction of FAD to form FADH2
There are 18 key atoms in isoalloxazine that make up its characteristic three-ring structure. The R-group varies and differentiates various flavins.
Approximate absorption spectrum for FAD
Riboflavin
Mechanism 1. Hydride transfer occurs by addition of H+ and 2 e−
Equilibrium between the oxidized (left) and totally reduced (right) forms of flavin.
Mechanism 2. Hydride transfer by abstraction of hydride from NADH
FAD
Mechanism 3. Radical formation by electron abstraction
FMN
Mechanism 4. The loss of hydride to electron deficient R group
Mechanism 5. Use of nucleophilic addition to break R1-R2 bond
Mechanism 6. Carbon radical reacts with O2 and acid to form H2O2
Riboflavin
FADH{{sub|2}}

A flavoprotein is a protein that contains a flavin group, which may be in the form of FAD or flavin mononucleotide (FMN).

- Flavin adenine dinucleotide

The flavin moiety is often attached with an adenosine diphosphate to form flavin adenine dinucleotide (FAD), and, in other circumstances, is found as flavin mononucleotide (or FMN), a phosphorylated form of riboflavin.

- Flavin group
Reaction of FAD to form FADH2

5 related topics with Alpha

Overall
The electron transport chain in the cell is the site of oxidative phosphorylation. The NADH and succinate generated in the citric acid cycle are oxidized, releasing the energy of O2 to power the ATP synthase.

Oxidative phosphorylation

1 links

Metabolic pathway in which cells use enzymes to oxidize nutrients, thereby releasing chemical energy in order to produce adenosine triphosphate (ATP).

Metabolic pathway in which cells use enzymes to oxidize nutrients, thereby releasing chemical energy in order to produce adenosine triphosphate (ATP).

The electron transport chain in the cell is the site of oxidative phosphorylation. The NADH and succinate generated in the citric acid cycle are oxidized, releasing the energy of O2 to power the ATP synthase.
Reduction of coenzyme Q from its ubiquinone form (Q) to the reduced ubiquinol form (QH2).
Complex I or NADH-Q oxidoreductase. The abbreviations are discussed in the text. In all diagrams of respiratory complexes in this article, the matrix is at the bottom, with the intermembrane space above.
Complex II: Succinate-Q oxidoreductase.
The two electron transfer steps in complex III: Q-cytochrome c oxidoreductase. After each step, Q (in the upper part of the figure) leaves the enzyme.
Complex IV: cytochrome c oxidase.
Mechanism of ATP synthase. ATP is shown in red, ADP and phosphate in pink and the rotating γ subunit in black.

The energy stored in the chemical bonds of glucose is released by the cell in the citric acid cycle producing carbon dioxide, and the energetic electron donors NADH and FADH.

Within proteins, electrons are transferred between flavin cofactors, iron–sulfur clusters and cytochromes.

Interactive animation of the structure of ATP

Adenosine triphosphate

1 links

Organic compound and hydrotrope that provides energy to drive many processes in living cells, such as muscle contraction, nerve impulse propagation, condensate dissolution, and chemical synthesis.

Organic compound and hydrotrope that provides energy to drive many processes in living cells, such as muscle contraction, nerve impulse propagation, condensate dissolution, and chemical synthesis.

Interactive animation of the structure of ATP
The cycles of synthesis and degradation of ATP; 2 and 1 represent input and output of energy, respectively.
This image shows a 360-degree rotation of a single, gas-phase magnesium-ATP chelate with a charge of −2. The anion was optimized at the UB3LYP/6-311++G(d,p) theoretical level and the atomic connectivity modified by the human optimizer to reflect the probable electronic structure.
An example of the Rossmann fold, a structural domain of a decarboxylase enzyme from the bacterium Staphylococcus epidermidis with a bound flavin mononucleotide cofactor.

Every "turn" of the citric acid cycle produces two molecules of carbon dioxide, one equivalent of ATP guanosine triphosphate (GTP) through substrate-level phosphorylation catalyzed by succinyl-CoA synthetase, as succinyl-CoA is converted to succinate, three equivalents of NADH, and one equivalent of FADH2.

NADH and FADH2 are recycled (to NAD+ and FAD, respectively) by oxidative phosphorylation, generating additional ATP.

Chemical structure

Riboflavin

0 links

Vitamin found in food and sold as a dietary supplement.

Vitamin found in food and sold as a dietary supplement.

Chemical structure
Cultures of Micrococcus luteus growing on pyridine (left) and succinic acid (right). The pyridine culture has turned yellow from the accumulation of riboflavin.

It is essential to the formation of two major coenzymes, flavin mononucleotide and flavin adenine dinucleotide.

The name "riboflavin" comes from "ribose" (the sugar whose reduced form, ribitol, forms part of its structure) and "flavin", the ring-moiety which imparts the yellow color to the oxidized molecule (from Latin flavus, "yellow").

Solution NMR structure of protein NMA1147 from Neisseria meningitidis. Northeast structural genomics consortium target mr19

Succinate dehydrogenase

0 links

Enzyme complex, found in many bacterial cells and in the inner mitochondrial membrane of eukaryotes.

Enzyme complex, found in many bacterial cells and in the inner mitochondrial membrane of eukaryotes.

Solution NMR structure of protein NMA1147 from Neisseria meningitidis. Northeast structural genomics consortium target mr19
Image 5: Subunits of succinate dehydrogenase
Image 6: E2 Succinate oxidation mechanism.
Image 7: E1cb Succinate oxidation mechanism.
Image 8: Ubiquinone reduction mechanism.
Image 9: Electron carriers of the SQR complex. FADH2, iron-sulfur centers, heme b, and ubiquinone.

SdhA contains a covalently attached flavin adenine dinucleotide (FAD) cofactor and the succinate binding site and SdhB contains three iron-sulfur clusters: [2Fe-2S], [4Fe-4S], and [3Fe-4S].

The function of SdhE has been described as a flavinator of succinate dehydrogenase.

hDAAO head-to-head connection

D-amino acid oxidase

0 links

Enzyme with the function on a molecular level to oxidize D-amino acids to the corresponding α-keto acids, producing ammonia and hydrogen peroxide.

Enzyme with the function on a molecular level to oxidize D-amino acids to the corresponding α-keto acids, producing ammonia and hydrogen peroxide.

hDAAO head-to-head connection
SchizophreniaBrain

It is also considered a peroxisomal enzyme containing FAD as a cofactor.

Human DAAO has slightly different properties from other DAAO molecules, including a weaker ability to bind FAD and decreased rate of reaction for some molecules, such as flavin.