Barrio J R, Secrist J A, Leonard N J
Proc Natl Acad Sci U S A. 1972 Aug;69(8):2039-42. doi: 10.1073/pnas.69.8.2039.
Nicotinamide 1,N(6)-ethenoadenine dinucleotide, a fluorescent analog of the coenzyme nicotinamide adenine dinucleotide, has been synthesized by the reaction of chloroacetaldehyde with the coenzyme. The technical fluorescence emission maximum of the analog is 410 nm, upon excitation at 300 nm. Its fluorescence yield is about 8% of that of the 1,N(6)-ethenoadenine 5'-phosphate, and its fluorescence lifteime is shorter. Upon hydrolysis of the modified coenzyme analog with Neurospora crassa NADase or phosphodiesterase I at room temperature, the intensity of fluorescence was increased 10-fold, corresponding to separation of the nicotinamide and ethenoadenine rings. The spectroscopic results with nicotinamide 1,N(6)-ethenoadenine dinucleotide are consistent with the concept of an intramolecular interaction between the modified adenine and pyridine moieties of the dinucleotide that is disrupted by enzymatic hydrolysis. The fluorescent analog showed reasonable activity as a substitute for NAD(+) in four different dehydrogenase-catalyzed reactions.
烟酰胺1,N(6)-乙烯腺嘌呤二核苷酸是辅酶烟酰胺腺嘌呤二核苷酸的一种荧光类似物，它是通过氯乙醛与该辅酶反应合成的。该类似物的技术荧光发射最大值在300nm激发时为410nm。其荧光产率约为1,N(6)-乙烯腺嘌呤5'-磷酸的8%，且其荧光寿命较短。在室温下用粗糙脉孢菌NAD酶或磷酸二酯酶I水解修饰的辅酶类似物时，荧光强度增加了10倍，这对应于烟酰胺和乙烯腺嘌呤环的分离。烟酰胺1,N(6)-乙烯腺嘌呤二核苷酸的光谱结果与二核苷酸中修饰的腺嘌呤和吡啶部分之间分子内相互作用的概念一致，这种相互作用会被酶促水解破坏。该荧光类似物在四种不同的脱氢酶催化反应中作为NAD(+)的替代物表现出合理的活性。
