McDonald L J, Moss J
Laboratory of Cellular Metabolism, National Heart, Lung, and Blood Institute, National Institutes of Health, Bethesda, MD 20892.
Mol Cell Biochem. 1994 Sep;138(1-2):201-6. doi: 10.1007/BF00928462.
Nitric oxide (NO) has been suggested to act as a regulator of endogenous intracellular ADP-ribosylation, based on radiolabelling of proteins in tissue homogenates incubated with [32P]NAD and NO. After the NO-stimulated modification was replicated in a defined system containing only the purified acceptor protein, glyceraldehyde-3-phosphate dehydrogenase (GAPDH), the hypothesis of NO-stimulation of an endogenous ADP-ribosyltransferase became moot. The NO-stimulated, NAD-dependent modification of GAPDH was recently characterized as covalent binding of the whole NAD molecule to the enzyme, not ADP-ribosylation. With this result, along with the knowledge that GAPDH is stoichiometrically S-nitrosylated, the role of NO in protein modification with NAD may be viewed as the conferring of an unexpected chemical reactivity upon GAPDH, possibly due to nitrosylation of a cysteine in the enzyme active site.
基于用[32P]NAD和一氧化氮（NO）孵育的组织匀浆中蛋白质的放射性标记，有人提出一氧化氮（NO）可作为内源性细胞内ADP-核糖基化的调节剂。在仅含有纯化的受体蛋白甘油醛-3-磷酸脱氢酶（GAPDH）的特定系统中复制了NO刺激的修饰后，关于NO刺激内源性ADP-核糖基转移酶的假说变得没有实际意义。最近，GAPDH的NO刺激的、NAD依赖性修饰被表征为整个NAD分子与该酶的共价结合，而非ADP-核糖基化。有了这一结果，再加上已知GAPDH在化学计量上被S-亚硝基化，NO在NAD对蛋白质修饰中的作用可被视为赋予GAPDH一种意外的化学反应性，这可能是由于该酶活性位点中的半胱氨酸发生了亚硝基化。
