肽链体系中的长程电子转移:多肽构象和旁链间距对电子转移矩阵元的影响  

Long-range Electron Transfer in Peptides: Influence of Peptide Conformation and Side Chain Separation upon Electron Transfer Element

作　　者：李象远[1] 易海波[1] 刘继凤[1] 佟静[1] 何福城[1] 

机构地区：[1]四川大学化工学院,成都610065

出　　处：《高等学校化学学报》2001年第12期2056-2060,共5页Chemical Journal of Chinese Universities

基　　金：国家自然科学基金 (批准号 :2 9892 16 4;39970 183)资助

摘　　要：用 AM1半经验方法 ,优化了吲哚和苯酚中性分子、正离子自由基和负离子自由基的几何构型 .用线性反应坐标近似和溶剂效应的类导体屏蔽模型 ( COSMO)构造吲哚正离子和苯酚中性分子间电子转移的双势阱 ,用以估算多肽链中色氨酸和酪氨酸之间的电子转移的反应热和内重组能 .优化 Trp H-( Pro) n-Tyr OH( n=0～ 3)多肽模型分子的结构和构象 ,用能级分裂因子的极小值方法计算了这些多肽体系的电子转移矩阵元 .The geometries of neutral indole and phenol, as well as their cation radicals and anion radicals, have been optimized by using AM1 method. In the double\|well potential constructions of the electron transfer (ET) between indole cation radical and neutral phenol, linear reaction coordinate approximation has been adopted, and the conductor\|like screening model has been involked. Based on the indole\|phenol double\|well potential, the reaction heat and the inner reorganization energy of ET between tryptophan and tyrosine have been evaluated. AM1 method has been applied to obtain the geometries and the conformations of TrpH\|(Pro)\-\{\%n\%\}\|TyrOH(\%n\%=0\_3) model systems. ET matrix elements for the intramolecular ET in those model peptides have been estimated through the determination of the minimum of the energy splitting factor.

关 键 词：长程电子转移 多肽 线性反应坐标 能级分裂因子 构象 旁链间距 电子转移矩阵元 AM1方法 

分 类 号：O629.72[理学—有机化学] Q516[理学—化学]