Amine Dehydrogenase (), also known as methylamine dehydrogenase (MADH), is a

tryptophan tryptophylquinone Tryptophan tryptophylquinone (TTQ) is an enzyme cofactor, generated by posttranslational modification of amino acid Amino acids are organic compounds that contain both amino and carboxylic acid functional groups. Although hundreds of amin ...

-dependent (TTQ-dependent)

enzyme Enzymes () are proteins that act as biological catalysts by accelerating chemical reactions. The molecules upon which enzymes may act are called substrates, and the enzyme converts the substrates into different molecules known as products. A ...

that

catalyzes Catalysis () is the process of increasing the rate of a chemical reaction by adding a substance known as a catalyst (). Catalysts are not consumed in the reaction and remain unchanged after it. If the reaction is rapid and the catalyst recyc ...

the

oxidative deamination Oxidative deamination is a form of deamination that generates α-keto acids and other oxidized products from amine-containing compounds, and occurs primarily in the liver. Oxidative deamination is stereospecific, meaning it contains different stere ...

of a primary amine to an

aldehyde In organic chemistry, an aldehyde () is an organic compound containing a functional group with the structure . The functional group itself (without the "R" side chain) can be referred to as an aldehyde but can also be classified as a formyl grou ...

and

ammonia Ammonia is an inorganic compound of nitrogen and hydrogen with the formula . A stable binary hydride, and the simplest pnictogen hydride, ammonia is a colourless gas with a distinct pungent smell. Biologically, it is a common nitrogenous was ...

. The reaction occurs as follows: RCH₂NH₂ + H₂O +

acceptor Acceptor may refer to: * Acceptor (accounting), the addressee of a bill of exchange * In the Indian Contract Act of 1872, the acceptor is the person to whom a proposal is made, and who has communicated his or her acceptance of the said proposal ...

→ RCHO + NH₃ + reduced acceptor Amine dehydrogenase possesses an α₂β₂ structure with each smaller β subunit possessing a TTQ protein cofactor. Amine dehydrogenase, studied in ''

Paracoccus denitrificans ''Paracoccus denitrificans'', is a coccoid bacterium known for its nitrate reducing properties, its ability to replicate under conditions of hypergravity and for being a relative of the eukaryotic mitochondrion (endosymbiotic theory). Descripti ...

'', at least transiently forms a ternary complex to catalyze methylamine-dependent cytochrome c-551i reduction. Within this complex, electrons are transferred from the TTQ cofactor of MADH to the Type 1 copper center of amicyanin, and then to the heme of the

cytochrome Cytochromes are redox-active proteins containing a heme, with a central Fe atom at its core, as a cofactor. They are involved in electron transport chain and redox catalysis. They are classified according to the type of heme and its mode of bin ...

References

External links

* EC 1.4.99 {{enzyme-stub