Molybdenum cofactor

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Molybdenum cofactor
Molybdenum cofactor.svg
Names
Other names
Moco
Identifiers
872689-63-9 YesY
DrugBank DB02137 YesY
Jmol-3D images Image
PubChem 25202532
Properties
C10H12MoN5O8PS2
Molar mass 521.27 g·mol−1
Except where noted otherwise, data is given for materials in their standard state (at 25 °C (77 °F), 100 kPa)
 YesY verify (what isYesY/N?)
Infobox references
Moco biosynthetic pathway in bacteria and humans. Molybdenum cofactor (Moco) biosynthesis occurs in four steps: (i) the radical-mediated cyclization of nucleotide, guanosine 5'-triphosphate (GTP), to (8S)‑3 ́,8‐cyclo‑7,8‑dihydroguanosine 5 ́‑triphosphate (3 ́,8‑cH2GTP), (ii) the formation of cyclic pyranopterin monophosphate (cPMP) from the 3 ́,8‑cH2GTP, (iii) the conversion of cPMP into molybdopterin (MPT), (iv) the insertion of molybdate into MPT to form Moco. The human enzymes are indicated in parenthesis.

Molybdenum cofactor (Moco) is a metal-containing Prosthetic group common to nearly all molybdoenzymes and is ubiquitous to all kingdoms of life. Moco-dependent enzymes play central roles in many biologically important processes such as purine and sulfur catabolism in mammals, anaerobic respiration in bacteria, and nitrate assimilation in plants. In humans, Moco deficiency results in the pleiotropic loss of activity of enzymes such as sulfite oxidase, xanthine oxidoreductase, and aldehyde oxidase, which in turn causes neurological abnormalities and early childhood death.[1][2][3] It is a coordination complex formed between molybdopterin (which, despite the name, does not contain molybdenum) and an oxide of molybdenum. The molybdenum in this cofactor is in its fully oxidized state (VI), similar to molybdenum in molybdate ion.

Unlike many other cofactors, Moco cannot be taken up as a nutrient, and thus requires de novo biosynthesic. Molybdenum cofactor biosynthesis occurs in four steps: (i) the radical-mediated cyclization of nucleotide, guanosine triphosphate (GTP), to (8S)‑3 ́,8‐cyclo‑7,8‑dihydroguanosine 5 ́‑triphosphate (3 ́,8‑cH2GTP), (ii) the formation of cyclic pyranopterin monophosphate (cPMP) from the 3 ́,8‑cH2GTP, (iii) the conversion of cPMP into molybdopterin (MPT), (iv) the insertion of molybdate into MPT to form Moco.[3][4]

Molybdenum cofactor functions directly in ethylbenzene dehydrogenase, glyceraldehyde-3-phosphate ferredoxin oxidoreductase, and respiratory arsenate reductase

In animals and plants these enzymes use molybdenum bound at the active site in a tricyclic molybdenum cofactor. All molybdenum-using enzymes so far identified in nature use this cofactor, save for the phylogenetically ancient molybdenum nitrogenases, which fix nitrogen in some bacteria and cyanobacteria.[5] Molybdenum enzymes in plants and animals catalyze the oxidation and sometimes reduction of certain small molecules, as part of the regulation of nitrogen, sulfur and carbon cycles.[6]

See also[edit]

References[edit]

  1. ^ Schwarz G (December 2005). "Molybdenum cofactor biosynthesis and deficiency". Cell. Mol. Life Sci. 62 (23): 2792–810. doi:10.1007/s00018-005-5269-y. PMID 16261263. 
  2. ^ Smolinsky B, Eichler SA, Buchmeier S, Meier JC, Schwarz G (June 2008). "Splice-specific functions of gephyrin in molybdenum cofactor biosynthesis". J. Biol. Chem. 283 (25): 17370–9. doi:10.1074/jbc.M800985200. PMID 18411266. 
  3. ^ a b Hover BM, Tonthat NK, Schumacher MA, Yokoyama K (May 2015). "Mechanism of pyranopterin ring formation in molybdenum cofactor biosynthesis". Pro Natl Acad Sci USA. PMID 25941396. 
  4. ^ Hover BM, Loksztejn A, Ribeiro AA, Yokoyama K (April 2013). "Identification of a cyclic nucleotide as a cryptic intermediate in molybdenum cofactor biosynthesis". J Am Chem Soc. 135 (18): 7019–32. doi:10.1021/ja401781t. PMID 23627491. 
  5. ^ "Structure, synthesis, empirical formula for the di-sulfhydryl". Retrieved 16 Nov 2009. 
  6. ^ Kisker, C.; Schindelin, H.; Baas, D.; Rétey, J.; Meckenstock, R.U; Kroneck, P.M.H (1999). "A structural comparison of molybdenum cofactor-containing enzymes". FEMS Microbiol. Rev. 22 (5): 503–521. doi:10.1111/j.1574-6976.1998.tb00384.x. PMID 9990727.