Raszka M, Kaplan N O
Proc Natl Acad Sci U S A. 1974 Nov;71(11):4546-50. doi: 10.1073/pnas.71.11.4546.
Data obtained by means of proton magnetic resonance spectroscopy indicate that specific association of FMN occurs with AMP in aqueous solution, because much weaker interaction is observed with FMN of either GMP or CMP. A comparison of FAD with a 1:1 mixture of FMN and AMP suggests that the flavin is involved in an intramolecular hydrogen bonding with the adenine moiety of FAD. The temperature dependence of chemical shifts would seem to indicate that the pyrophosphate linkage acts to reinforce stacking interactions as well as hydrogen bonding in the coenzyme. The linkage also limits the number of cyclic hydrogen bonding configurations, and a model is proposed to describe a fraction of unstacked FAD in aqueous solution.A parallel study was made of NAD(+) and its analogues; in contrast to FAD, no clear evidence of cyclic hydrogen bonding was obtained with the pyridine coenzymes.
通过质子磁共振波谱法获得的数据表明，在水溶液中，FMN与AMP发生特异性缔合，因为观察到FMN与GMP或CMP的相互作用要弱得多。将FAD与FMN和AMP的1:1混合物进行比较表明，黄素参与了与FAD腺嘌呤部分的分子内氢键形成。化学位移的温度依赖性似乎表明，焦磷酸键起到加强辅酶中堆积相互作用以及氢键的作用。该键还限制了环状氢键构型的数量，并提出了一个模型来描述水溶液中部分未堆积的FAD。对NAD(+)及其类似物进行了平行研究；与FAD不同，未获得吡啶辅酶形成环状氢键的明确证据。
