Betaine-homocysteine methyltransferase is a zinc metallo-enzyme that catalyzes the transfer of a methyl group from betaine to homocysteine to produce dimethylglycine and methionine respectively:[1]
- betaine + homocysteine → dimethylglycine + methionine
Methionine in turn can donate the methyl group to methylate DNA, proteins, lipids, and other intracellular metabolites.
Isozymes
In humans, there are two isozymes, BHMT[2][3] and BHMT2,[4][5] each encoded by a separate gene.
Tissue distribution
BHMT is expressed most predominantly in the liver and kidney.[6]
Clinical significance
Anomalies in homocysteine metabolism have been implicated in disorders ranging from vascular disease to neural tube birth defects such as spina bifida.
See also
References
- ^ Pajares MA, Pérez-Sala D (December 2006). "Betaine homocysteine S-methyltransferase: just a regulator of homocysteine metabolism?". Cell. Mol. Life Sci. 63 (23): 2792–803. doi:10.1007/s00018-006-6249-6. PMID 17086380.
- ^ Garrow TA (September 1996). "Purification, kinetic properties, and cDNA cloning of mammalian betaine-homocysteine methyltransferase". J. Biol. Chem. 271 (37): 22831–8. PMID 8798461. http://www.jbc.org/cgi/pmidlookup?view=long&pmid=8798461.
- ^ Sunden SL, Renduchintala MS, Park EI, Miklasz SD, Garrow TA (September 1997). "Betaine-homocysteine methyltransferase expression in porcine and human tissues and chromosomal localization of the human gene". Arch. Biochem. Biophys. 345 (1): 171–4. doi:10.1006/abbi.1997.0246. PMID 9281325.
- ^ Chadwick LH, McCandless SE, Silverman GL, Schwartz S, Westaway D, Nadeau JH (November 2000). "Betaine-homocysteine methyltransferase-2: cDNA cloning, gene sequence, physical mapping, and expression of the human and mouse genes". Genomics 70 (1): 66–73. doi:10.1006/geno.2000.6319. PMID 11087663.
- ^ Szegedi SS, Castro CC, Koutmos M, Garrow TA (April 2008). "Betaine-homocysteine S-methyltransferase-2 is an S-methylmethionine-homocysteine methyltransferase". J. Biol. Chem. 283 (14): 8939–45. doi:10.1074/jbc.M710449200. PMID 18230605.
- ^ Sunden SL, Renduchintala MS, Park EI, Miklasz SD, Garrow TA (September 1997). "Betaine-homocysteine methyltransferase expression in porcine and human tissues and chromosomal localization of the human gene". Arch. Biochem. Biophys. 345 (1): 171–4. doi:10.1006/abbi.1997.0246. PMID 9281325.
External links
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