Adenosylmethionine, Adenosylhomocysteine and Related Nucleosides

摘要: The function of l-methionine as a methyl group donor in biological transmethylation reactions requires ATP to form so-called active methionine. This compound was identified S-adenosyl-l-methionine (AdoMet) by Cantoni (1952, 1953), who showed, with liver preparation, that it synthesized the enzyme, methionine adenosyltransferase (EC 2.5.1.6) through follow¬ing reaction: $$L - + \to AdoMet PPi Pi$$ AdoMet is most versatile for many systems both prokaryotic and eukaryotic organisms, whereas 5-methyltetrahydrofolic acid, methylcobalamine betaine are involved relatively few methylation reactions. Many low molecular weight metabolic compounds receive from catalyzed AdoMet-dependent transmethylases. These include catechols, norepinephrine, histamine, serotonine, tryptamine, so on. Much attention has recently been paid membrane phospholipids relation regulation structure function. proteins, RNAs DNAs also suggested play important roles cell differentiation, protein synthesis, carcinogenesis Such versatility suggests they very cellular regulations. In this respect, can be comparable phosphorylation