Adenosylcobalamin (original) (raw)

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Biologically active form of vitamin B12

Pharmaceutical compound

Adenosylcobalamin

Clinical data
AHFS/Drugs.com International Drug Names
Routes of administration Oral
ATC code B03BA04 (WHO)
Legal status
Legal status US: OTC
Identifiers
IUPAC name Coα-[α-(5,6-dimethylbenzimidazolyl)]-Coβ-(5'-deoxy-5'-adenosyl)cobamide
CAS Number 13870-90-1 checkY
PubChem CID 5459907
ChemSpider 16736117 checkY
UNII F0R1QK73KB
KEGG D00042 checkY
ChEBI CHEBI:18408 ☒N
CompTox Dashboard (EPA) DTXSID1046009 Edit this at Wikidata
ECHA InfoCard 100.034.192 Edit this at Wikidata
Chemical and physical data
Formula C72H100CoN18O17P
Molar mass 1579.608 g·mol−1
InChI InChI=1S/C62H90N13O14P.C10H12N5O3.Co/c1-29-20-39-40(21-30(29)2)75(28-70-39)57-52(84)53(41(27-76)87-57)89-90(85,86)88-31(3)26-69-49(83)18-19-59(8)37(22-46(66)80)56-62(11)61(10,25-48(68)82)36(14-17-45(65)79)51(74-62)33(5)55-60(9,24-47(67)81)34(12-15-43(63)77)38(71-55)23-42-58(6,7)35(13-16-44(64)78)50(72-42)32(4)54(59)73-56;1-4-6(16)7(17)10(18-4)15-3-14-5-8(11)12-2-13-9(5)15;/h20-21,23,28,31,34-37,41,52-53,56-57,76,84H,12-19,22,24-27H2,1-11H3,(H15,63,64,65,66,67,68,69,71,72,73,74,77,78,79,80,81,82,83,85,86);2-4,6-7,10,16-17H,1H2,(H2,11,12,13);/q;;+2/p-2/t31?,34?,35?,36?,37?,41-,52-,53-,56?,57+,59?,60?,61?,62?;4-,6-,7-,10-;/m11./s1 checkYKey:ZIHHMGTYZOSFRC-CXGXMSGESA-L checkY
☒NcheckY (what is this?) (verify)

Adenosylcobalamin (AdoCbl), also known as coenzyme B12, cobamamide, and dibencozide, is one of the biologically active forms of vitamin B12.[1]

Schematic diagram of the propionate metabolic pathway. Adenosylcobalamin is required as a coenzyme by the methylmalonyl-CoA mutase in order to convert L-methylmalonyl-CoA into succinyl-CoA, otherwise methylmalonic acid accumulates.

Adenosylcobalamin participates as a cofactor in radical-mediated 1,2-carbon skeleton rearrangements. These processes require the formation of the deoxyadenosyl radical through homolytic dissociation of the carbon-cobalt bond. This bond is exceptionally weak, with a bond dissociation energy of 31 kcal/mol, which is further lowered in the chemical environment of an enzyme active site.[2] An enzyme that uses adenosylcobalamin as a coenzyme is methylmalonyl-CoA mutase (MCM).

Further experimentation has also determined adenosylcobalamin's role in regulating expression of some bacterial genes. By binding to CarH,[_clarification needed_] AdoCbl can modulate carotenoid genes, which confer warm colors onto various plants. Carotenoid transcription is activated by sunlight, due to the response from AdoCbl.[3] There are other photoreceptors across different bacterial communities, aside from CarH, that also have reactive capability when bound to AdoCbl. For instance, AerR is another factor that uses AdoCbl to give off purple pigmentation. Additional examination of adenosylcobalamin-bound enzymes and the development of this cofactor over time may prove to hold regulatory function of DNA and RNA.[4]

  1. ^ Marsh EN, Meléndez GD (November 2012). "Adenosylcobalamin enzymes: theory and experiment begin to converge". Biochimica et Biophysica Acta (BBA) - Proteins and Proteomics. 1824 (11): 1154–1164. doi:10.1016/j.bbapap.2012.03.012. PMC 3580769. PMID 22516318.
  2. ^ Kräutler B, Arigoni D, Golding BT (1998). Vitamin B12 and B12-proteins : lectures presented at the 4th European Symposium on Vitamin B12 and B12-Proteins. Weinheim: Wiley-VCH. ISBN 9783527612192. OCLC 212131311.
  3. ^ Jost M (April 1, 2015). "An Old Cofactor in a New Light: Adenosylcobalamin in Light-Dependent Gene Regulation". The FASEB Journal. 29. doi:10.1096/fasebj.29.1_supplement.573.25. S2CID 89044509.
  4. ^ Chemaly SM (October 2016). "New light on vitamin B12: The adenosylcobalamin-dependent photoreceptor protein CarH". South African Journal of Science. 112 (9–10): 9. doi:10.17159/sajs.2016/20160106. S2CID 90441731.