Methanol esterification reactions catalyzed by snake venom and bovine intestinal 5'-nucleotide phosphodiesterases. Formation of nucleoside 5'-monophosphate methyl esters from guanosine 5'-triphosphate and other nucleoside 5'-polyphosphates.
It is not known whether the enzymes 5'-nucleotide phosphodiesterase/nucleotide pyrophosphatase (EC 3.1.4.1/EC 3.6.1.9) catalyze the transfer of nucleotides to acceptors other than water. We have investigated the action of snake venom and bovine intestinal mucosa phosphodiesterases on nucleoside 5'-polyphosphates in the presence of methanol. In those conditions, GTP was converted by snake venom phosphodiesterase to a mixture of GMP and another compound with a different retention time in reverse-phase high-performance liquid chromatography. That compound, by ultraviolet, 1H- and 13C-nuclear magnetic resonance spectroscopic analysis, and by enzyme analysis, was characterized as the methyl ester of GMP (GMP-OMe). The molar fraction [GMP-OMe]/[GMP + GMP-OMe] formed was higher than the molar fraction of methanol as a solvent in reaction mixtures. Similar reactions took place at comparable rates with snake venom and bovine intestinal mucosa phosphodiesterases using several nucleoside 5'-polyphosphates as substrates. The ability of 5'-nucleotide phosphodiesterases to catalyze transfer reactions to a non-water acceptor is relevant to the mechanism of the enzymes, to their use as analytical tools, and to their possible use/role in the preparative/in vivo synthesis of nucleotide esters.
Garcia-Diaz
M
M
Departamento de Bioquímica y Biología Molecular y Genética, Facultad de Medicina, Universidad de Extremadura, Badajoz, Spain.
Avalos
M
M
Cameselle
J C
JC
D000818:Animals; D002384:Catalysis; D002851:Chromatography, High Pressure Liquid; D004951:Esterification; D006157:Guanosine Monophosphate / Q000031:analogs & derivatives / Q000096:biosynthesis / Q000378:metabolism; D006160:Guanosine Triphosphate / Q000378:metabolism*; D007413:Intestinal Mucosa / Q000201:enzymology; D009682:Magnetic Resonance Spectroscopy; D000432:Methanol / Q000378:metabolism; D009711:Nucleotides / Q000378:metabolism*; D043264:Phosphodiesterase I; D010727:Phosphoric Diester Hydrolases / Q000378:metabolism*; D013056:Spectrophotometry, Ultraviolet
D009711:Nucleotides; C068010:guanosine 5'-monophosphate methyl ester; D006157:Guanosine Monophosphate; D006160:Guanosine Triphosphate; D010727:Phosphoric Diester Hydrolases; D043264:Phosphodiesterase I; C470790:phosphodiesterase I, snake venom; D000432:Methanol