结构生物学研究方法的重大突破——电子直接探测相机在冷冻电镜中的应用

Revolutionary Breakthrough of Structure Determination——Recent Advances of Electron Direct Detection Device Application in Cryo-EM

近年来,科学家应用冷冻电镜技术（cryo-EM）解析出了低对称性生物大分子的高分辨率（3~5魡）三维结构,并用其密度图直接进行了分子建模。与传统的X-射线和NMR方法相比,冷冻电镜技术具有适用于分子量较大的生物分子、样品不需结晶且用量很少等优势。尤其是电子直接探测相机（electron direct detection device,DDD）在冷冻电镜技术中的应用,使高分辨率的结构研究变得更加简单、应用更为广泛,是一个重大突破。文章介绍DDD相机的原理和技术优势,及其在解决冷冻电镜技术困难中的一些应用,进而展望了DDD相机可能给冷冻电镜技术应用带来的突破性进展。

Recent advances in Cryo-EM have made it possible to solve numerous structures of asymmetric macromolecules at high resolution （3-5A）, allowing for de novo modeling. In comparison to NMR and X-ray methods, cryo-EM possesses a remarkable advantage for studying large macromolecules, requiring small amounts of material and no crystallization of the macromolecules being studied. Its tremendous progress mainly results from the application of electron direct detection device cameras （DDD） to record images. This review introduces the principle and advantages of DDD first, and then explains how this technique helps to conquer the difficulties encountered in the filed in combination with our cryo-EM experience. Some prospects of using DDD to get more fantastic results are also included.