Triazinylaniline derivatives as fluorescence probes. Part 4. Kinetics and selectivity in the reactions of N,N-diethyl-4-(dichloro-1,3,5-triazinyl)aniline with amines, amino acids and proteins relevant to fluorescence labelling
作者:David J. Cowley
DOI:10.1039/p29960002431
日期:——
The kinetics of reaction of the reactive triazinyl dye, N,N-diethyl-4-(dichloro-1,3,5-triazinyl)aniline with primary and secondary amines, amino acids, and the proteins bovine brain calmodulin and bovine serum albumin in aqueous media, as monitored by UV–VIS absorption spectroscopy, are reported. In general the reaction is first-order in the dye and in the substrate. Secondary aliphatic amines are
反应性三嗪基染料N,N -N-二乙基-4-(dichloro-1,3,5-三嗪基)苯胺与伯胺和仲胺,氨基酸以及牛脑钙调蛋白和牛血清白蛋白的反应动力学报告了通过UV-VIS吸收光谱法监测的水性介质。通常,反应在染料和底物中是一级的。仲脂族胺比伯脂族胺更具反应性,并且在许多情况下观察到双羟基取代基的阻滞作用。染料对赖氨酸侧链α-氨基的固有反应性比游离N高10倍-末端氨基。已经确定了pH和温度对反应速率的影响。染料(TACl 2)与钙调蛋白和牛血清白蛋白赖氨酸残基的反应选择性分别为1:1和≈2:1染料-蛋白质化学计量比,这归因于染料和蛋白质的疏水相互作用表面。基于动力学证据,提出了一个三阶段机理并进行了数值评估。染料和蛋白质的初始快速扩散相遇之后,是染料在蛋白质的疏水口袋中的较慢的“内在化”(活化能65-77 kJ mol -1)。最后,化学加合物的形成发生在蛋白质内部,其活化能为21–36 kJ