|Systematic (IUPAC) name|
|CAS Registry Number|
|Molecular mass||1344.40 g/mol|
Methylcobalamin (mecobalamin, MeCbl, or MeB12) is a cobalamin, a form of vitamin B12. It differs from cyanocobalamin in that the cyanide is replaced by a methyl group. Methylcobalamin features an octahedral cobalt(III) centre. Methylcobalamin can be obtained as bright red crystals. From the perspective of coordination chemistry, methylcobalamin is notable as a rare example of a compound that contains metal-alkyl bonds. Nickel-methyl intermediates have been proposed for the final step of methanogenesis.
- Production 1
- Functions 2
- See also 3
- References 4
This vitamer is one of two active coenzymes used by vitamin B12-dependent enzymes and is the specific vitamin B12 form used by 5-methyltetrahydrofolate-homocysteine methyltransferase (MTR), also known as methionine synthase.
Methylcobalamin participates in the
- L. R. McDowell, Vitamins in animal and human nutrition
- David Dophin. Preparation of the Reduced Forms of Vitamin B12 and of Some Analogs of the Vitamin B12 Coenzyme Containing a Cobalt-Carbon Bond. D.B. McCormick and L.D. Wright, Eds. 1971;Vol. XVIII:34-54.
- Fontecilla-Camps, J. C.; Amara, P.; Cavazza, C.; Nicolet, Y.; Volbeda, A. (2009). "Structure–function relationships of anaerobic gas-processing metalloenzymes". Nature 460 (7257): 814–822.
- Zenon Schneider, Andrzej Stroiński, Comprehensive B12: Chemistry, Biochemistry, Nutrition, Ecology, Medicine
- Bémeur, Chantal; et al. (2011). Blass, John P., ed. Neurochemical Mechanisms in Disease. Springer. pp. 112–3.
A lack of methylcobalamin can lead to megaloblastic anemia and subacute combined degeneration of the spinal cord.
Methylcobalamin is produced by some bacteria. It plays an important role in the environment. In the environment, it is responsible for the biomethylation of certain heavy metals. For example, the highly toxic methylmercury is produced by the action of methylcobalamin. In this role, methylcobalamin serves as a source of "CH3+".