自由能微扰法用于α-环糊精对氨基酸的手性识别研究

Chiral recognition of amino acids byα-cyclodextrin using free energy perturbation calculation

利用基于NAMD的自由能微扰方法(free energy perturbation,FEP)计算了α-环糊精与4种氨基酸对映体的相对结合自由能。结果表明：计算结果与实验结果可得到相同的结论,即α-环糊精对L型氨基酸具有较高的选择性,且识别能力的顺序与实验结果也基本一致。因此,相对结合自由能计算可作为α-环糊精对氨基酸对映体手性识别的依据。

Based on molecular dynamics software NAMD, free energy perturbation （FEP） calculation were carried out to predict the relative binding energy of the complex of four amino acids and α-cyclodextrin. Starting structures of both host and guest molecules were optimized with global optimization method, and the dynamic calculation was carried out in NPT ensemble. Results indicated that the recognition results by FEP calculation are in a good agreement with the experimental ones, i.e. the selectivity to L-isomer is higher than D-isomer. Furthermore, the sequential order of the recognition ability of the four studied amino acids is also almost consistent with the experimental results. FEP calculation may provide a convenient tool for chiral recognition studies.