Amine oxidase (copper-containing)

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amine oxidase
Identifiers
EC number 1.4.3.6
CAS number 9001-53-0
Databases
IntEnz IntEnz view
BRENDA BRENDA entry
ExPASy NiceZyme view
KEGG KEGG entry
MetaCyc metabolic pathway
PRIAM profile
PDB structures RCSB PDB PDBe PDBsum
Gene Ontology AmiGO / EGO
Copper amine oxidase, enzyme domain
3LOY.pdb.png
Crystal structure of a copper-containing benzylamine oxidase from Hansenula polymorpha.[1]
Identifiers
Symbol Cu_amine_oxid
Pfam PF01179
InterPro IPR015798
PROSITE PDOC00895
SCOP 1oac
SUPERFAMILY 1oac
Copper amine oxidase N-terminal domain
PDB 1d6u EBI.jpg
crystal structure of e. coli amine oxidase anaerobically reduced with beta-phenylethylamine
Identifiers
Symbol Cu_amine_oxidN1
Pfam PF07833
InterPro IPR012854
SCOP 1spu
SUPERFAMILY 1spu
Copper amine oxidase, N2 domain
PDB 1ksi EBI.jpg
crystal structure of a eukaryotic (pea seedling) copper-containing amine oxidase at 2.2a resolution
Identifiers
Symbol Cu_amine_oxidN2
Pfam PF02727
Pfam clan CL0047
InterPro IPR015800
PROSITE PDOC00895
SCOP 1oac
SUPERFAMILY 1oac
Copper amine oxidase, N3 domain
PDB 2oqe EBI.jpg
crystal structure of hansenula polymorpha amine oxidase in complex with xe to 1.6 angstroms
Identifiers
Symbol Cu_amine_oxidN3
Pfam PF02728
Pfam clan CL0047
InterPro IPR015802
PROSITE PDOC00895
SCOP 1oac
SUPERFAMILY 1oac

Amine oxidases (AO) are enzymes that catalyze the oxidation of a wide range of biogenic amines including many neurotransmitters, histamine and xenobiotic amines. There are two classes of amine oxidases: flavin-containing (EC 1.4.3.4) and copper-containing (EC 1.4.3.6). Copper-containing AO act as a disulphide-linked homodimer. They catalyse the oxidation of primary amines to aldehydes, with the subsequent release of ammonia and hydrogen peroxide, which requires one copper ion per subunit and topaquinone as cofactor:[2]

RCH2NH2 + H2O + O2 \rightleftharpoons RCHO + NH3 + H2O2

The 3 substrates of this enzyme are primary amines (RCH2NH2), H2O, and O2, whereas its 3 products are RCHO, NH3, and H2O2.

Copper-containing amine oxidases are found in bacteria, fungi, plants and animals. In prokaryotes, the enzyme enables various amine substrates to be used as sources of carbon and nitrogen.[3][4]

This enzyme belongs to oxidoreductases, specifically those acting on the CH-NH2 group of donors with oxygen as acceptor. The systematic name of this enzyme class is amine:oxygen oxidoreductase (deaminating) (copper-containing). This enzyme participates in 8 metabolic pathways: urea cycle and metabolism of amino groups, glycine, serine and threonine metabolism, histidine metabolism, tyrosine metabolism, phenylalanine metabolism, tryptophan metabolism, beta-alanine metabolism, and alkaloid biosynthesis ii. It has 2 cofactors: copper, and PQQ.

Structure[edit]

The copper amine oxidase 3-dimensional structure was determined through X-ray crystallography.[1] The copper amine oxidases occur as mushroom-shaped homodimers of 70-95 kDa, each monomer containing a copper ion and a covalently bound redox cofactor, topaquinone (TPQ). TPQ is formed by post-translational modification of a conserved tyrosine residue. The copper ion is coordinated with three histidine residues and two water molecules in a distorted square pyramidal geometry, and has a dual function in catalysis and TPQ biogenesis. The catalytic domain is the largest of the 3-4 domains found in copper amine oxidases, and consists of a beta sandwich of 18 strands in two sheets. The active site is buried and requires a conformational change to allow the substrate access.

The N2 and N3 N-terminal domains share a common structural fold, its core consisting of alpha-beta(4), where the helix is packed against the coiled anti-parallel beta-sheets. An additional domain is found at the N-terminal of some copper amine oxidases, as well as in related proteins such as cell wall hydrolase and N-acetylmuramoyl-L-alanine amidase. This domain consists of a five-stranded antiparallel beta-sheet twisted around an alpha helix.[5][6]

Function[edit]

In eukaryotes they have a broader range of functions, including cell differentiation and growth, wound healing, detoxification and cell signalling[7] as well as functioning as a vascular adhesion protein (VAP-1) in some mammalian tissues.[1]

Human proteins containing this domain[edit]

ABP1; AOC2; AOC3;

See also[edit]

References[edit]

  1. ^ a b c PDB 3LOY; Chang CM, Klema VJ, Johnson BJ, Mure M, Klinman JP, Wilmot CM (March 2010). "Kinetic and structural analysis of substrate specificity in two copper amine oxidases from Hansenula polymorpha". Biochemistry 49 (11): 2540–50. doi:10.1021/bi901933d. PMC 2851405. PMID 20155950. 
  2. ^ Convery MA, Phillips SE, McPherson MJ, Yadav KD, Knowles PF, Parsons MR, Wilmot CM, Blakeley V, Corner AS (1995). "Crystal structure of a quinoenzyme: copper amine oxidase of Escherichia coli at 2 A resolution". Structure 3 (11): 1171–1184. doi:10.1016/s0969-2126(01)00253-2. PMID 8591028. 
  3. ^ Murray JM, Convery MA, Phillips SE, McPherson MJ, Knowles PF, Parsons MR, Wilmot CM, Blakeley V, Corner AS, Alton G, Palcic MM (1997). "Catalytic mechanism of the quinoenzyme amine oxidase from Escherichia coli: exploring the reductive half-reaction". Biochemistry 36 (7): 1608–1620. doi:10.1021/bi962205j. PMID 9048544. 
  4. ^ Tanizawa K, Guss JM, Freeman HC, Yamaguchi H, Wilce MC, Dooley DM, Matsunami H, Mcintire WS, Ruggiero CE (1997). "Crystal structures of the copper-containing amine oxidase from Arthrobacter globiformis in the holo and apo forms: implications for the biogenesis of topaquinone". Biochemistry 36 (51): 16116–16133. doi:10.1021/bi971797i. PMID 9405045. 
  5. ^ Parsons MR, Convery MA, Wilmot CM, Yadav KD, Blakeley V, Corner AS, Phillips SE, McPherson MJ, Knowles PF (November 1995). "Crystal structure of a quinoenzyme: copper amine oxidase of Escherichia coli at 2 A resolution". Structure 3 (11): 1171–84. doi:10.1016/s0969-2126(01)00253-2. PMID 8591028. 
  6. ^ Wilmot CM, Hajdu J, McPherson MJ, Knowles PF, Phillips SE (November 1999). "Visualization of dioxygen bound to copper during enzyme catalysis". Science 286 (5445): 1724–8. doi:10.1126/science.286.5445.1724. PMID 10576737. 
  7. ^ Guss JM, Freeman HC, Kumar V, Wilce MC, Dooley DM, Harvey I, Mcguirl MA, Zubak VM (1996). "Crystal structure of a eukaryotic (pea seedling) copper-containing amine oxidase at 2.2 A resolution". Structure 4 (8): 943–955. doi:10.1016/s0969-2126(96)00101-3. PMID 8805580. 

Further reading[edit]