S adenosylehomocysteine is the product that is resulted from the AdoMet depenedent transmethylation
reactions, SAM is converted into S-adenosylhomocysteine (SAH) and then hydrolyzed to adenosine and Hcy.
, glycine and sarcosine are interconvertible.
Hcy can be harmful to cells because it evokes oxidative stress through the production of reactive oxidative stress through the production of reactive oxygen species, binds to nitric oxide, or leads to the accumulation of its precursor, S-adenosylhomocysteine, a protein inhibitor of biological transmethylation
. A study  reported that the maternal hHcy was correlated with fetal CHD; therefore, maternal MTHFR 677C>T and MTRR 66A>G polymorphisms, which would induce high blood level of Hcy, should have effects on fetal CHD development.
Considered by some authors as an important independent risk factor of atherosclerosis, Hcy can influence the atherosclerosis process in various aspects, through transmethylation
, endothelial injury, inflammation response, and oxidative stress .
Christie, "A simple procedure for rapid transmethylation
of glycerolipids and cholesteryl esters," Journal of Lipid Research, vol.
A metabolic disorder of vitamin B12 dependent transmethylation
pathway induced by HIV or cytokine activation is considered the possible cause of vacuolar myelopathy associated with AIDS.
The authors would like to thank Funcap, CNPq and Capes for their financial support and scholarships; to the Chemistry Laboratory of Natural Products and Biotechnology of the Federal University of Ceara, for GC/MS of esters obtained by transmethylation
of fish fatty acids, were analyzed.
The fatty acid composition of the frying oils was determined by gas chromatography (GC) of fatty acid methyl esters (FAME) prepared by transmethylation
with BF3/methanol at 100[degrees]C for 45 min .
Hcyis recycled into methionine by a transmethylation
reaction requiring vitamin B12 and folate.
SAM2 encodes an enzyme that catalyzes the formation of S-adenosylmethionine, an important cofactor in cellular transmethylation
Homocysteine is a by-product formed in the biologic transmethylation
reactions and detoxified with the methionine synthetase, which is the enzyme depending on vitamin B12, B6, and folate as coenzymes for proper functioning S-adenosylmethionine and methylation.