ABSTRACT
S-Adenosylmethionine (AdoMet), discovered by J.Cantoni in 1953, is a sulphonium compound found in all living cells. This molecule is a substrate or precursor in at least four classes of enzymatic transfer reactions
1. its adenosyl group is transferred to tripolyphosphate in the reversal of AdoMet synthetase reaction (Mudd and Mann, 1963);
2. its 3-amino-3-carboxyl group is transferred to special uridylate residues of certain bacterial tRNA (Nishimura et al., 1974);
3. its aminopropyl group after decarboxylation is transferred in polyamine biosynthesis (Tabor et al., 1961); and
4. its methyl group is transferred to different classes of compounds including proteins (Paik and Kim, 1974), nucleic acids (Borek and Srinivasan, 1965; Vanyushin et al., 1970), phospholipids (Bremmer and Greenberg, 1961; Hirata and Axelrod, 1980) and small molecules such as biogenic amines (Axelrod and Tomchick, 1958).
