The present study consists in a novel computational protocol to model the UV-circular dichroism spectra of solvated species. It makes use of quantum-chemical calculations on a series of conformations of a flexible chromophore or on a series of chromophore/solvent clusters extracted from molecular dynamic simulations. The protocol is described and applied to the aqueous cationic tripeptide GAG⁺ and to the aqueous neutral decapeptide (GVGVP)₂. The protocol has proven able to: (i) properly consider the conformational motion of solute in the given environment; (ii) give the actual statistical weight of each conformational state; (iii) provide a reliable quantum mechanical method able to reproduce the spectral features. Temperature effects on conformations and spectral properties are properly taken into account. The role of explicit solvent on the conformational analysis and the spectra calculation is discussed. The comparison of the calculated circular dichroism spectra with experimental ones recorded at different temperatures represents a strict validation test of the method.

中文翻译：

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溶剂化生色团电子圆二色性建模的计算方法

本研究包含一个新的计算协议，用于模拟溶剂化物种的紫外-圆二色谱。它对柔性发色团的一系列构象或从分子动力学模拟中提取的一系列发色团/溶剂簇进行量子化学计算。该协议被描述并应用于水性阳离子三肽 GAG ⁺和水性中性十肽 (GVGVP) ₂. 该协议已被证明能够：（i）正确考虑给定环境中溶质的构象运动；(ii) 给出每个构象状态的实际统计权重；(iii) 提供一种能够再现光谱特征的可靠的量子力学方法。适当考虑了温度对构象和光谱特性的影响。讨论了显式溶剂在构象分析和光谱计算中的作用。将计算的圆二色光谱与在不同温度下记录的实验光谱进行比较，代表了对该方法的严格验证测试。