Goor R S, Pappenheimer A M
J Exp Med. 1967 Nov 1;126(5):913-21. doi: 10.1084/jem.126.5.913.
The ability of a number of nucleotides related to NAD to replace NAD as cofactors for inhibition by diphtheria toxin of peptide bond formation has been examined. Neither NADH nor NADP are active. Of some 14 analogues closely related structurally to NAD that have been tested, only 3-thiocarboxamide pyridine-AD is as active as NAD itself. Replacement of the 3-carboxamide group on the pyridine ring by an acetyl group, or deamination of the purine ring, resulted in derivatives with reduced activity. The results were interpreted as suggesting that NAD and certain related nucleotides are capable of specific interaction with diphtheria toxin. Using the method of equilibrium dialysis, reversible binding of 1 mole of NAD per mole of toxin has been demonstrated. Toxoid does not interact with NAD.
已对一些与烟酰胺腺嘌呤二核苷酸(NAD)相关的核苷酸作为辅因子替代NAD以抑制白喉毒素对肽键形成的能力进行了研究。烟酰胺腺嘌呤二核苷酸磷酸(NADH)和烟酰胺腺嘌呤二核苷酸磷酸(NADP)均无活性。在已测试的约14种结构上与NAD密切相关的类似物中,只有3-硫代甲酰胺吡啶-AD与NAD本身活性相同。吡啶环上的3-甲酰胺基团被乙酰基取代,或嘌呤环脱氨基,会产生活性降低的衍生物。这些结果被解释为表明NAD和某些相关核苷酸能够与白喉毒素发生特异性相互作用。使用平衡透析法,已证明每摩尔毒素可与1摩尔NAD发生可逆结合。类毒素不与NAD相互作用。