Each lipid extract underwent basic transmethylation
in duplicate using potassium hydroxide in MeOH, following Ichihara's procedure (Ichihara et al.
Hcy metabolized through the transsulfuration and transmethylation
pathways, where folate, vitamin B-12 and vitamin B-6 are involved as a substrate or cofactor.
Thus, an acid-catalysed treatment of SPE converts both BFA and FFA into FAME, allowing the measurement of all individual fatty acids regardless of their initial form (free or bound); following alkali-catalysed transmethylation
, only the bound fatty acids are converted into FAME.
A simple procedure for rapid transmethylation
of glycerolipids and cholesteryl esters.
Addition of homocystine to the diet probably increases tHcy directly and leads to a product excess in methionine metabolism, inhibiting transmethylation
and thereby the utilization of methionine.
Prior to transmethylation
, a fixed amount of heneicosanoic acid (C21; Sigma Co.
TMG upregulates a host of enzymes and recycles homocysteine to methionine and enhances transmethylation
It is noteworthy that the formation of creatinine from methylation of guanidinoacetate accounts for approximately 75% of all folate-dependent transmethylation
reactions (Barr et al.
Effects of the disruption of transmethylation
in the central nervous system: an animal model.
Methionine-adenosyl-transferases are enzymes involved in transmethylation
Currently, several pharmacological mechanisms of methotrexate action have been suggested, including inhibition of purine and pyrimidine synthesis, suppression of transmethylation
reactions with accumulation of polyamines, reduction of antigen-dependent T-cell proliferation, and promotion of adenosine release with adenosine-mediated suppression of inflammation.
The importance of the transmethylation
pathway in the central nervous system has been outlined (5, 6).