冠丙四肽与前周期ⅥA和ⅦA阴离子结合作用的密度泛函法研究  

Theoretical study on the combination of crown tetraalanylpeptide with small ⅥA and ⅦAions based on B3LYP

作　　者：宋宏涛[1] 蒋树斌[1] 杨玉青[1] 魏洪源[1] 

机构地区：[1]中国工程物理研究院核物理与化学研究所,四川绵阳621900

出　　处：《计算机与应用化学》2012年第5期634-638,共5页Computers and Applied Chemistry

基　　金：中国工程物理研究院核物理与化学研究所科技创新基金(2009CX02);国防基础科研计划(B1520110007)

摘　　要：冠肽是环肽的特殊构型,其结构中的酰胺键主链呈规则排列,形成类似于冠醚的冠型构象,具有高度的对称性,易于形成实现与离子/分子结合的孔径或通道,达到预期的识别作用以及作为超分子离子载体的运输能力。用密度泛函理论的B3LYP方法,以环丙四肽的冠状构象(冠丙四肽)为模型基础,在真空体系中,对其与卤族氧族阴离子结合体系进行了几何构型优化、能量、Mulliken布局数、前沿轨道等方面的理论研究。结果表明:冠丙四肽的构型在与离子结合前后几乎没有改变,结合过程中电子由非金属阴离子移向冠肽主体,价键作用表现为阴离子与氨基氢之间的氢键作用,其中氟与冠型环丙四肽的结合作用并不特别明显优于氯和溴,而氧与冠型环丙四肽的结合作用则明显优于硫和硒;同等情况下,与二价离子的结合作用更显为显著。Abstract： Crown peptide is a kind of special conformation of the homodctic cyclopcptide, in the structure of which there is regular array about the main chain containing imido groups, and the channels or apertures can form more easily in order to recognize certain ion or molecular, and the function of intending dual-recognition and the ability for transporting as ionophores can be achieved. The density functional theory based hybrid-method B3LYP has been used to investigate the combination of the small VIA and VIA ions with crown tctraalanylpeptide which is the coronary structures of homodetic cyclotetraalapeptide and has been represented as the model basic. Several properties including combination energy, optimum geometry structures, and so on has been calculated. It is shown that the coronary structure was no change between C4-AIa and C4-AIa-X or C4-Ala-X（-II）.The electrons move from ions to C4-AIa during the combine process, Combination with C4-Ala, O（-II） is more predominant than S（-II） and Se（-II）, remarkably. The distances between VIA ions and the center of C4-Ala are 0.200 rim, 0.325 run and 0.325 nm, respectively, when the energy of C4-Ala-X（-II） at minimum. The distances between halogen ions and the center of C4-Ala are 0.250 nm, 0.330 nm and 0.350 nm, respectively, when the energy of C4-AIa-X- at minimum; besides, the combination of bivalent ions has advantage over univalent ones.

关 键 词：冠丙四肽 卤素阴离子 氧族阴离子 密度泛函理论 结合作用 

分 类 号：Q52[生物学—生物化学] O641.3[理学—物理化学]