α/β类蛋白折叠中π-π相互作用的特异性

Specificity of π-π Interactions in α/β Protein Folding

以α/β类蛋白的2种典型折叠类型为研究对象,对205个低相似度蛋白样本中的π-π相互作用进行统计分析.计算结果表明,(α/β)8-barrel折叠中π-π相互作用的分布密度高于经典Rossmann折叠,且在关键的局部区域的差异更加显著;芳香族氨基酸在(α/β)8-barrel结构中更容易形成π-π相互作用;色氨酸对应的3种π-π相互作用组合在(α/β)8-barrel折叠中出现的几率显著高于经典Rossmann折叠;(α/β)8-barrel折叠中π-π相互作用形成复杂π网络的能力强于经典Rossmann折叠.上述结果表明,π-π相互作用在α/β类蛋白的不同折叠类型中存在特异性,其在稳定(α/β)8-barrel结构中的作用强于经典Rossmann折叠.

Protein folding study is one of the main ways to investigate structural stability and mechanism of proteins. π-π Interaction has been focused much attention on its role in the stability of protein structure and functions. In this paper, two typical protein folds of α/β protein were selected for the research,π-πinterac-tions of 205 low similarity protein samples were statistically analyzed. The results showed that the distribution density of π-π interactions in （α/β） 8-barrel fold was higher than those of classical Rossmann fold and the difference was more significant in the critical local area, aromatic amino acids easily form π-πinteractions in （α/β） 8-barrel, the threeπ-πinteraction combinations corresponding to Trp appearing in （α/β） 8-barrel were significantly higher than classic Rossmann and （α/β） 8-barrel fold had greater ability to form complex π-net-work than classical Rossmann fold. In a word,π-πinteractions in different folding types of α/β protein exist specificity. π-π Interaction effects the stability of （α/β） 8-barrel stronger than the classical Rossmann.