蛋白质磁共振——从结构生物学到结构基因组学

NMR with proteins-from structural biology to structural genomics

在后基因组时代,随着大量物种全基因组序列的获得,结构生物学家面临着结构基因组学的新机遇和挑战。与传统的结构生物学不同的是,结构基因组学的研究主要集中在结构和功能未知并且与从前研究的蛋白质相似性很小的蛋白质。准确的来讲,结构基因组学通过高通量蛋白质表达、结构解析来完成所有蛋白质家族的结构表征,从而能够通过结构预测功能。加州结构基因组学联合实验室发展了高度自动化的蛋白质合成、结晶、结构解析生产线。然而由于一些蛋白质不能被结晶,要想覆盖所有蛋白质结构域还有很大困难。Wuthrich的研究小组通过一些高通量的目的蛋白质筛选和NMR结构解析的方法解决了这一难题。与X射线晶体学解析蛋白质结构相比,NMR技术由于能够解析更接近生理状态的溶液结构而具有互补性。通过获得溶液中的蛋白质稳定性、动力学特征和相互作用信息,正如在朊蛋白和SARS相关蛋白的研究中所表现的那样,NMR技术从扩大已知的蛋白质结构数据库、新的蛋白质功能到化学生物学研究中都扮演着激动人心的角色。

In post-genomic era,with the availability of the complete DNA sequences of a wide range of organisms,structural biologists are faced with new opportunities and challenges in structural genomics.In contrast to classical structural biology,research in structural genomics is focused on gene products with unknown structures,unknown functions,and minimal similarity to previously studied proteins.A precisely formulated goal of structural genomics is to determine representative three-dimensional structures for all protein families,which requires ＇higt-hroughput＇ technology for protein production and structure determination,and the long-term outlook is to predict physiological protein functions from knowledge of new three-dimensional structures.The California-based Joint Center for Structure Genomics（JCSG） is one of the four large-scale consortia in the NIH-funded Protein Structure Initiative（PSI）,which developed and operates an extensively automated high-throughput pipeline for protein production,crystallization and crystal structure determination.However,there remain gaps in the coverage of protein fold space that are due to certain proteins being not readily amenable to crystal structure determination.Wuthrich＇s research team works on filling such gaps with a high-output approach,which involves novel strategies of target selection as well as new technology for NMR structure determination.When compared to structure determination by X-ray crystallography,the NMR method is complementary by the fact that atomic resolution structure and other function-related data can be measured under solution conditions close to the physiological milieu in body fluids.By generating data on protein structure stability,dynamics and intermolecular interactions in solution,NMR has an exciting role also in the longer-term challenge leading from the expanding protein universe to new insights into protein functions and chemical biology.As illustrations,structural genomics traits of research on prion proteins and SARS-CoV will be discussed.