阳离子-π相互作用在两种典型蛋白质折叠型中的偏好性  

The Preference of Cation-π Interactions in Two Typical Protein Folds

作　　者：乔辉[1] 李晓琴[1] 徐海松[1] 孔令强[1] 

机构地区：[1]北京工业大学生命科学与生物工程学院,北京100124

出　　处：《生物信息学》2011年第1期76-81,共6页Chinese Journal of Bioinformatics

基　　金：国家自然科学基金(30570427);北京市自然科学基金(4092008)资助项目

摘　　要：阳离子-π相互作用是一种在阳离子和芳香性体系之间形成的一种作用力。在蛋白质中,带正电荷的氨基酸(Lys、Arg)和芳香族氨基酸(Phe、Tyr、Trp)之间可以形成阳离子-π相互作用。对α/β类蛋白中两种典型折叠类型――单绕和双绕的研究表明:(1)单绕结构中阳离子-π相互作用的分布密度是双绕结构的2.3倍。(2)Arg-Phe组合偏好在双绕中出现,Arg-Tyr组合偏好在单绕中出现。(3)在单绕中除Lys-Phe组合外,其余5种组合的阳离子-π相互作用能量高于双绕的对应组合,其中以Arg-Trp组合的能量最高。(4)在单绕结构中,样本所含氨基酸残基数量和样本中阳离子-π的数量有明显的相关性,在双绕结构中没有发现类似的相关性。(5)在单绕和双绕结构当中,把阳离子-π相互作用能量分解为静电能和范德华力能揭示出静电能与范德华力能之比接近2∶1,静电作用在阳离子-π相互作用中起主要作用。Cation-π interaction is a force which exist between cation and aromatic group.In proteins,the cation-π interactions can be formed between the positively charged amino acids （Lys,Arg） and aromatic amino acids（Phe,Tyr,Trp）.We investigated the cation-π interaction in two types of typical folding structures in α/β proteins,namely,the singly wound structure and the doubly wound structure.The results reveal that： （1） The distribution density of cation-π interactions in singly wound structure is 2.3 fold higher than in doubly wound structure.（2） The Arg-Phe pairs incline to doubly wound structure while the Arg-Tyr pairs prefer in singly wound structure.（3） Except the Lys-Phe pairs,the other five type pairs possess higher energy in singly wounds structure than their doubly wound counterparts,and the Arg-Trp pairs have the highest energy among those types of pairs.（4）In singly wound structure,a correlation is observed between the amount of residues and their cation-π interactions,while no correlation is observed in doubly wound structure.（5）In those singly wound and doubly wound typical structures,the cation-π interactions energy can be separated into the electrostatic energy and the van der Waals energy,the electrostatic energy plays a major role in cation-π interactions,which has approximately 2 fold energy higher than the van der Waals energy.

关 键 词：单绕 双绕 阳离子-Π相互作用 

分 类 号：O641[理学—物理化学]