Organophosphorus -adenosyl--methionine mimetics: synthesis, stability, and substrate properties.

-Adenosyl-l-methionine (SAM)-mediated methylation of biomolecules controls their function and regulates numerous vital intracellular processes. Analogs of SAM with a reporter group in place of the -methyl group are widely used to study these processes. However, many of these analogs are chemically unstable that largely limits their practical application. We have developed a new compound, , which contains an phosphinic group (-P(O)(H)OH) instead of the SAM carboxylic group. is significantly more stable than SAM, retains functional activity in catechol-O-methyltransferase and methyltransferase WBSCR27 reactions. The last is associated with Williams-Beuren syndrome. - was synthesized chemically, while ()- and its analogs were prepared enzymatically either from -phosphinic analogs of methionine (Met-P) or -phosphinic analog of -adenosyl-l-homocysteine ( ) using methionine adenosyltransferase 2A or halide methyltransferases, respectively. undergoes glycoside bond cleavage in the presence of methylthioadenosine nucleosidase like natural SAH. Thus, and its analogs are promising new tools for investigating methyltransferases and incorporating reporter groups into their substrates.