蛋白质三级拓扑结构对热稳定性贡献的初步探讨

Preliminary Study on the Contribution of Protein Structure Topology to Thermostability

搜集来自数据库和文献的127个已测定熔解温度和PDB结构的热稳定蛋白,计算了每个蛋白PDB结构的9种拓扑参数,并对各个参数与其自身熔解温度做了线性相关性分析。现有数据结果表明只有CC这个参数与Tm的相关性系数达到了0.33。CC参数表征蛋白结构作为天然接触的网络来处理时的簇系数,因此这一关系表明组成蛋白的基团接触的越紧密,蛋白的热稳定性就越高,这与之前的研究结论相一致。而其它的参数没有发现与Tm有显著的关系。作者从拓扑结构这个方面进行研究为蛋白质的热适应机理研究提供了新的思路。

In the present work, nine topological parameters for 127 proteins with 3D structures and melting temperatures（Tin）, collected from databases and the literature, were calculated. Then the linear relationship between each parameter and Tm was analyzed. Topological parameter ＂CC＂ is defined as the clustering coefficient by treating protein structure as a network of native contacts. It was observed that the correlation coefficient between topological parameter ＂CC＂ and Tm is as high as 0.33, indicating that proteins display a higher thermostability with more compact group contacts, which is consistent with the previous studies. However, no significant correlation was observed between Trn and the other parameters. This work provides a new insight into the research of the mechanism of protein thermal adaptation.