由锰离子依赖的ADP-核糖/CDP-醇焦磷酸酶催化的环ADP-核糖磷酸酐键的水解
Hydrolysis of the phosphoanhydride linkage of cyclic ADP-ribose by the Mn(2+)-dependent ADP-ribose/CDP-alcohol pyrophosphatase.
作者信息
Canales José, Fernández Ascensión, Rodrigues Joaquim Rui, Ferreira Rui, Ribeiro João Meireles, Cabezas Alicia, Costas María Jesús, Cameselle José Carlos
机构信息
Grupo de Enzimología, Departamento de Bioquímica y Biología Molecular y Genética, Facultad de Medicina, Universidad de Extremadura, Badajoz, Spain.
出版信息
FEBS Lett. 2009 May 19;583(10):1593-8. doi: 10.1016/j.febslet.2009.04.023. Epub 2009 Apr 18.
Cyclic ADP-ribose (cADPR) metabolism in mammals is catalyzed by NAD glycohydrolases (NADases) that, besides forming ADP-ribose, form and hydrolyze the N(1)-glycosidic linkage of cADPR. Thus far, no cADPR phosphohydrolase was known. We tested rat ADP-ribose/CDP-alcohol pyrophosphatase (ADPRibase-Mn) and found that cADPR is an ADPRibase-Mn ligand and substrate. ADPRibase-Mn activity on cADPR was 65-fold less efficient than on ADP-ribose, the best substrate. This is similar to the ADP-ribose/cADPR formation ratio by NADases. The product of cADPR phosphohydrolysis by ADPRibase-Mn was N(1)-(5-phosphoribosyl)-AMP, suggesting a novel route for cADPR turnover.
哺乳动物体内的环磷酸腺苷核糖（cADPR）代谢由烟酰胺腺嘌呤二核苷酸糖基水解酶（NADases）催化，这些酶除了形成二磷酸腺苷核糖（ADP-核糖）外，还能形成并水解cADPR的N(1)-糖苷键。到目前为止，尚未发现有cADPR磷酸水解酶。我们对大鼠二磷酸腺苷核糖/胞苷二磷酸醇焦磷酸酶（ADPRibase-Mn）进行了测试，发现cADPR是ADPRibase-Mn的配体和底物。ADPRibase-Mn对cADPR的活性比对最佳底物ADP-核糖的活性低65倍。这与NADases形成ADP-核糖/cADPR的比例相似。ADPRibase-Mn对cADPR进行磷酸水解的产物是N(1)-(5-磷酸核糖基)-AMP，这表明cADPR周转存在一条新途径。
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