Schoetz G, Trapp O, Schurig V
Universität Tübingen, Institut für Organische Chemie, Germany.
Electrophoresis. 2001 Aug;22(12):2409-15. doi: 10.1002/1522-2683(200107)22:12<2409::AID-ELPS2409>3.0.CO;2-C.
Dynamic capillary electrophoresis (DCE) and computer simulation of the elution profiles with the theoretical plate and the stochastic model has been applied to determine the isomerization barriers of the three dipeptides L-alanyl-L-proline, L-leucyl-L-proline, and L-phenylalanyl-L-proline. The separation of the rotational cis-trans isomers has been performed in an aqueous 70 mM borate buffer at pH 9.5. Interconversion profiles featuring plateau formation and peak broadening were observed. To determine the rate constants k1 and k(-1) of the cis-trans isomerization in dynamic capillary electrophoresis, equations have been derived for the theoretical plate model and stochastic model. The electropherograms were simulated with the ChromWin software which uses the experimental data plateau height h(plateau), peak width at half height Wh, the total migration times of the cis-trans isomers tR and the electroosmotic break-through time t0 as well as the peak ratio [cis]/[trans]. From temperature-dependent measurements, the rate constants k1 and k(-1) and the kinetic activation parameters deltaG#, deltaH# and deltaS# of the cis-trans isomerization of the three dipeptides were obtained.
动态毛细管电泳（DCE）以及使用理论塔板和随机模型对洗脱曲线进行计算机模拟，已被用于确定三种二肽L-丙氨酰-L-脯氨酸、L-亮氨酰-L-脯氨酸和L-苯丙氨酰-L-脯氨酸的异构化势垒。旋转顺反异构体的分离是在pH 9.5的70 mM硼酸盐缓冲水溶液中进行的。观察到了具有平台形成和峰展宽特征的相互转化曲线。为了确定动态毛细管电泳中顺反异构化的速率常数k1和k(-1)，已推导了理论塔板模型和随机模型的方程。使用ChromWin软件模拟电泳图，该软件使用实验数据平台高度h(plateau)、半高峰宽Wh、顺反异构体的总迁移时间tR和电渗突破时间t0以及峰比[顺式]/[反式]。通过温度依赖性测量，获得了三种二肽顺反异构化的速率常数k1和k(-1)以及动力学活化参数ΔG#、ΔH#和ΔS#。
