Synthesis of pyridine nucleotide analogs using rabbit spleen pyridine nucleotide glycohydrolase and stereospecificity of the transglycosidation reaction.
Seven pyridine nucleotide analogs were synthesized, including nicotinic acid mononucleotide, nicotinic acid-adenine dinucleotide, and nicotinic acid-adenine dinucleotidephosphate, by means of the transglycosidase activity of rabbit spleen pyridine nucleotide glycohydrolase. The velocity ratio of the transglycosidation to the hydrolysis in the presence of 16 mM nicotinamide mononucleotide and 0.3 M nicotinic acid at pH 5.2 was greater than 10 and the transglycosidation/hydrolysis partition ratio was estimated to be (12 +/- 2) x 10(3). The partition ratio values obtained with 3-acetylpyridine and nicotinylglycine were smaller than that with nicotinic acid. Configurational analysis of pyridinium C-N glycosidic linkages of the transglycosidation products by means of 1H-NMR, UV, CD, and paper chromatography indicated that the configuration was completely retained and absolutely beta. Retention of the configuration, together with the substrate specificity of the enzyme for the beta-pyridinium linkage and formation of the intermediary enzyme-phosphoribosyl (or ADP-ribosyl) complex during the enzyme catalysis, indicated that the transglycosidation reaction catalyzed by the enzyme proceeds through the double replacement mechanism.
Imai
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Department of Applied Biological Science, School of Agricultural Sciences, Nagoya University.
D000818:Animals; D002384:Catalysis; D002417:Cattle; D002942:Circular Dichroism; D006027:Glycosides / Q000737:chemistry*; D009682:Magnetic Resonance Spectroscopy; D008968:Molecular Conformation; D009243:NAD / Q000031:analogs & derivatives* / Q000138:chemical synthesis; D009244:NAD+ Nucleosidase / Q000737:chemistry*; D011817:Rabbits; D013154:Spleen / Q000737:chemistry*
D006027:Glycosides; D009243:NAD; D009244:NAD+ Nucleosidase