Zhang J, Snyder S H
Department of Neuroscience, Johns Hopkins University School of Medicine, Baltimore, MD 21205.
Proc Natl Acad Sci U S A. 1992 Oct 15;89(20):9382-5. doi: 10.1073/pnas.89.20.9382.
Nitric oxide generation in brain cytosolic fractions markedly enhances ADP-ribosylation of a single 37-kDa protein. By utilizing a biotinylated NAD and avidin affinity chromatography, we purified this protein. Partial amino acid sequencing establishes its identity as glyceraldehyde-3-phosphate dehydrogenase (GAPDH). This is further confirmed by detection of GAPDH enzymatic activity in the purified 37-kDa protein. GAPDH is ADP-ribosylated in the absence of brain extract. This auto-ADP-ribosylation is enhanced by nitric oxide generation. ADP-ribosylation appears to involve the cysteine where NAD interacts with GAPDH so that ADP-ribosylation likely inhibits enzymatic activity. Such inhibition may play a role in nitric oxide-mediated neurotoxicity.
脑细胞质组分中一氧化氮的生成显著增强了一种单一的37 kDa蛋白质的ADP核糖基化。通过使用生物素化的NAD和抗生物素蛋白亲和层析，我们纯化了这种蛋白质。部分氨基酸测序确定其为甘油醛-3-磷酸脱氢酶（GAPDH）。纯化的37 kDa蛋白质中GAPDH酶活性的检测进一步证实了这一点。在没有脑提取物的情况下，GAPDH会发生ADP核糖基化。一氧化氮的生成会增强这种自动ADP核糖基化。ADP核糖基化似乎涉及NAD与GAPDH相互作用的半胱氨酸，因此ADP核糖基化可能会抑制酶活性。这种抑制可能在一氧化氮介导的神经毒性中起作用。
