Bodley J W, Upham R, Crow F W, Tomer K B, Gross M L
Arch Biochem Biophys. 1984 May 1;230(2):590-3. doi: 10.1016/0003-9861(84)90439-9.
Diphtheria toxin inactivates protein synthesis elongation factor 2 by attaching ADP-ribose to an unusual post-translational amino acid derivative, diphthamide, in the factor. Previously, we prepared ribosyl-diphthamide from the ADP-ribosyl-factor and proposed on the basis of NMR spectral analysis that it is 1-alpha-D-ribofuranosyl-2-[3-carboxyamido-3-(trimethylammonio++ +)propyl] histidine [N. J. Oppenheimer, and J.W. Bodley, (1981) J. Biol. Chem. 256, 8579-8581 and op. cit.]. Now, using fast atom bombardment mass spectrometry, the intact cation of ribosyl-diphthamide has been observed in the gas phase. The theoretical mass of the structure proposed for ribosyl-diphthamide uniquely agrees with the observed mass of the inact cation of the compound to within 2 ppm. Collisional activation decomposition mass spectral analysis provided additional structural confirmation. Thus, although the compound has not been synthesized, all available evidence appears uniquely consistent with the structure of ribosyl-diphthamide previously proposed.
白喉毒素通过将ADP - 核糖连接到该因子中一种不寻常的翻译后氨基酸衍生物——白喉酰胺上，使蛋白质合成延伸因子2失活。此前，我们从ADP - 核糖基因子制备了核糖基 - 白喉酰胺，并基于核磁共振光谱分析提出它是1 - α - D - 呋喃核糖基 - 2 - [3 - 羧酰胺基 - 3 - （三甲基铵基）丙基]组氨酸[N. J. 奥本海默和J. W. 博德利，（1981年）《生物化学杂志》256，8579 - 8581及同引文献]。现在，使用快原子轰击质谱法，已在气相中观察到核糖基 - 白喉酰胺的完整阳离子。为核糖基 - 白喉酰胺提出的结构的理论质量与该化合物失活阳离子的观察质量在2 ppm范围内唯一一致。碰撞活化分解质谱分析提供了额外的结构确认。因此，尽管该化合物尚未合成，但所有现有证据似乎都与先前提出的核糖基 - 白喉酰胺结构唯一一致。
