Wieczorek Z, Stepinski J, Jankowska M, Lönnberg H
Department of Physics and Biophysics, University of Agriculture and Technology, Olsztyn, Poland.
J Photochem Photobiol B. 1995 Apr;28(1):57-63. doi: 10.1016/1011-1344(94)07098-9.
Absorption and fluorescence properties of several cap analogues, namely nucleosides, nucleoside 5'-monophosphates and P1,P3-dinucleoside triphosphates derived from 7-methylguanine, N2,7-dimethylguanine and N2,N2,7-trimethylguanine, have been studied. The data obtained include the absorption and fluorescence spectra of the cationic (N1-protonated) and zwitterionic (N1-deprotonated) species, the pKa values of the ground and excited states of the methylated base moiety and the effect of temperature and solvent composition (mixtures of water and 1,4-dioxane) on the fluorescence intensity. Furthermore, the fluorescence lifetimes of N2,N2,7-trimethylguanosine 5'-triphosphate and P1-guanosine(5')-P3-[N2,N2,7-trimethylguanosine(5')] triphosphate have been determined as a function of temperature. These data clearly indicate that dynamic quenching must be taken into account when the extent of the intramolecular stacking of the latter compound is estimated by fluorescence spectroscopy.
对几种帽类似物的吸收和荧光特性进行了研究，这些类似物即由7-甲基鸟嘌呤、N2,7-二甲基鸟嘌呤和N2,N2,7-三甲基鸟嘌呤衍生而来的核苷、核苷5'-单磷酸酯和P1,P3-二核苷三磷酸酯。所获得的数据包括阳离子（N1-质子化）和两性离子（N1-去质子化）物种的吸收和荧光光谱、甲基化碱基部分基态和激发态的pKa值以及温度和溶剂组成（水和1,4-二氧六环的混合物）对荧光强度的影响。此外，还测定了N2,N2,7-三甲基鸟苷5'-三磷酸酯和P1-鸟苷(5')-P3-[N2,N2,7-三甲基鸟苷(5')]三磷酸酯的荧光寿命随温度的变化情况。这些数据清楚地表明，当通过荧光光谱法估计后一种化合物的分子内堆积程度时，必须考虑动态猝灭。
