Pasternack R F, Fleming C, Herring S, Collings P J, dePaula J, DeCastro G, Gibbs E J
Department of Chemistry, Swarthmore College, Swarthmore Pennsylvania 19081, USA.
Biophys J. 2000 Jul;79(1):550-60. doi: 10.1016/S0006-3495(00)76316-8.
The kinetics of J-aggregate formation has been studied for two chromophores, tetrakis-4-sulfonatophenylporphine in an acid medium and pseudoisocyanine on a polyvinylsulfonate template. The assembly processes differ both in their sensitivity to initiation protocols and in the reaction profiles they produce. The porphyrin's assembly kinetics, for example, displays an induction period unlike that of the cyanine dye. Two kinetic models are presented. For the porphyrin, an autocatalytic pathway in which the formation of an aggregation nucleus is rate-determining appears to be applicable; for the pseudoisocyanine dye, an equation derived for diffusion-limited aggregation of a fractal object satisfactorily fits the data. These models are shown to be useful for the analysis of kinetic data obtained for several biologically important aggregation processes.
针对两种发色团，即酸性介质中的四（4 - 磺酸苯基）卟啉和聚乙烯磺酸盐模板上的假异氰吲哚，研究了J - 聚集体形成的动力学。这两种组装过程在对引发方案的敏感性以及所产生的反应曲线方面均有所不同。例如，卟啉的组装动力学表现出与花青染料不同的诱导期。本文提出了两种动力学模型。对于卟啉而言，一种以聚集核形成作为速率决定步骤的自催化途径似乎适用；对于假异氰吲哚染料，一个为分形物体的扩散限制聚集推导出来的方程能够令人满意地拟合数据。结果表明，这些模型对于分析从几个具有生物学重要性的聚集过程中获得的动力学数据很有用。
