Genazzani A A, Bak J, Galione A
Department of Pharmacology, Oxford University, United Kingdom.
Biochem Biophys Res Commun. 1996 Jun 25;223(3):502-7. doi: 10.1006/bbrc.1996.0924.
Cyclic adenosine 5'-diphosphate ribose (cADPR) is a potent Ca2+ releasing agent in a number of tissues. A particular bifunctional NAD+ glycohydrolase is responsible for both the cyclase and hydrolase activity necessary for its synthesis from beta-NAD and degradation to ADPR. We now report that ADPR, the end-product of this enzyme, releases Ca2+ at high concentrations (above 100 microM), and at lower concentrations (10-100 microM) inhibits the hydrolysis of cADPR and potentiates the production of cADPR from NAD+. This evidence suggests that ADPR may be an important modulator of the NAD+ glycohydrolase responsible for the production of cADPR.
环腺苷酸5'-二磷酸核糖（cADPR）在许多组织中是一种有效的钙离子释放剂。一种特殊的双功能烟酰胺腺嘌呤二核苷酸（NAD+）糖水解酶负责从β-NAD合成cADPR以及将其降解为腺苷二磷酸核糖（ADPR）所需的环化酶和水解酶活性。我们现在报告，这种酶的终产物ADPR在高浓度（高于100微摩尔）时释放钙离子，而在较低浓度（10 - 100微摩尔）时抑制cADPR的水解，并增强NAD+生成cADPR的过程。这一证据表明，ADPR可能是负责生成cADPR的NAD+糖水解酶的重要调节剂。
