EMISSION PROPERTIES OF NADH . STUDIES OF FLUORESCENCE LIFETIMES AND QUANTUM EFFICIENCIES OF NADH, ACPYADH, AND SIMPLIFIED SYNTHETIC MODELS
EMISSION PROPERTIES OF NADH . STUDIES OF FLUORESCENCE LIFETIMES AND QUANTUM EFFICIENCIES OF NADH, ACPYADH, AND SIMPLIFIED SYNTHETIC MODELS
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DOI：
10.1021/ja00706a043
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发表时间：
1970-01-01
影响因子：
15
通讯作者：
WEBER, G
中科院分区：
文献类型：
--
作者：
SCOTT, TG;SPENCER, RD;WEBER, G
2在0-30 ℃范围内测定了NADH、AcPyADH和模型化合物Ad-C3-NicH、Ad-Ce-NicH在水和1，2-丙二醇溶液中的荧光寿命和量子效率q。对于Ad-C3-NicH、NADH和Ad-C6-NicH，在25 ° C下在水中的绝对量子效率分别为0.035、0.019和0.017，精确到百分之几，并且寿命分别为0.70、0.40、和0.28±0.03 ~ 0.05nsec。用荧光偏振观测法计算了基态到最低单重态跃迁对吸收光谱的贡献，并且从这些和分子荧光光谱，通过Strickler和贝格的公式计算了发射寿命Te。对于不同条件下的NADH和AcPyADH，在量子效率变化30倍时，严格遵循关系式r= req。通过与这些衍生物的比较或通过q= r/re的关系测定，硫酸奎宁的绝对效率为0.70±0.02，而不是经常引用的0.55。对于Ad-C3-NicH、NADH和Ad-C6-NicH，在25 ℃水溶液中观察到的从腺嘌呤到二氢烟酰胺部分的能量转移的量子效率如下：分别为0.44、0.34和0.10。对于这三种化合物，从温度依赖性的寿命计算的无辐射跃迁的速率和活化能的比较表明，淬火过程基本上是identicalin 1，2-丙二醇，但在水溶液中不同，表明在水中的相互作用，但不是在1，2-丙二醇，是每个化合物的特征和具体。通过连二亚硫酸盐还原具有氧化形式烟酰胺化的相应前体，制备了简化的光谱模型Ad-C3-NicH和Ad-Ce-NicH，其被设计为通过将NADH的茶烯基和二氢烟酰胺部分与三链和三链连接来并入NADH的吸收-发射发色团。
2 The fluorescence lifetimes and quantum efficiencies q of NADH, AcPyADH, and of the model com-pounds Ad-C3-NicH and Ad-Ce-NicH have been measured in water and in 1, 2-propanediol solution in the temperature range 0-30. For Ad-C3-NicH, NADH, and Ad-C6-NicH at 25 in water the absolute quantum efficiencies are 0.035, 0.019, and 0.017, respectively, to a precision of a few per cent, and the lifetimes are 0.70, 0.40, and 0.28±0.03 to 0.05 nsec The contribution of the ground to lowest singlet transition to the absorption spectrum has beenevaluated by fluorescence polarization observations, and from these and the molecular fluorescence spectra, emissive lifetimes Te have been calculated by the equation of Strickler and Berg. For NADH and AcPyADH under various con-ditions, the relation r= req is followed rigorously over a thirtyfold change in quantum efficiency. The absolute efficiency of quinine sulfate measured either by comparisonwith these derivatives or by the relation q= r/re turns out to be 0.70±0.02 rather than the often quoted 0.55. The observed quantum efficiencies of energy transfer from the adenine to the dihydronicotinamide moiety were as follows for Ad-C3-NicH, NADH, and Ad-C6-NicH at 25 in aqueous solution: 0.44, 0.34, and 0.10, respectively. For these threecompounds, comparison of the rates and of the energies of activation for radiationless transitions calculated from the temperature dependence of the lifetimes shows that the quenching processes are essentially identicalin 1, 2-propanediol but different in aqueous solution, indicating that interactions in water, but not in 1, 2-propanediol, are characteristic and specific for each compound. The simplified spectroscopic models, Ad-C3-NicH and Ad-Ce-NicH, which were designed to incorporate the absorption-emission chromophores of NADH by linking theadenyl and dihydronicotinamide moieties of NADH with triand hexamethylene chains, were prepared by dithionite reduction of the corresponding precursors possessing the nicotinamidering in oxidized form.