Equipe de Chimie et Biochimie Théoriques, UMR 7565 CNRS-UHP, Institut Jean Barriol (FR CNRS 2843), Faculté des Sciences et Techniques, Nancy-Université, Vandoeuvre-lès-Nancy Cedex, France.
Interdiscip Sci. 2010 Mar;2(1):38-47. doi: 10.1007/s12539-010-0084-z. Epub 2010 Jan 28.
Mutation on Enhanced Cyan Fluorescent Protein (ECFP) has been investigated by means of a hybrid quantum mechanics and molecular mechanics (QM/MM) approach. A simple model, which represents the electronic response of the surroundings (ERS) by a polarizable continuum characterized by the relative dielectric constant extrapolated to infinite frequency, is used. For all mutations, this method (QM/MM+ERS) reproduces the experimental trend (shift) and is in correct agreement with experimental maximum absorption wavelength (between -10 and +10 nm). The effect of the ECFP on the optical properties is analyzed and decomposed into three major contributions (geometric deformation, electrostatic polarization and electronic response). It is shown that these three contributions have similar magnitude and one cannot neglect one with respect to the others. In addition, these contributions differ greatly from one chromophore to another showing that the same protein framework acts differently on different chromophores.
通过混合量子力学和分子力学（QM/MM）方法研究了增强型青色荧光蛋白（ECFP）的突变。使用了一种简单的模型，该模型通过相对介电常数外推至无限频率来表示环境的极化连续体（ERS）的电子响应。对于所有突变，该方法（QM/MM+ERS）再现了实验趋势（位移），并且与实验最大吸收波长（在-10nm 到+10nm 之间）相符。分析了 ECFP 对光学性质的影响，并将其分解为三个主要贡献（几何变形、静电极化和电子响应）。结果表明，这三个贡献具有相似的大小，不能忽略其中一个相对于其他贡献。此外，这些贡献在不同的发色团之间有很大的差异，表明相同的蛋白质框架对不同的发色团有不同的作用。
