The Rise of the Low Temperature Electron
Microscope
The most influential annual technology in 2015: single particle low temperature
electron microscopy (cryo-EM). This is a young but potential development for
protein three-dimensional structure determination and protein rational design ,
beyond X-ray crystallography and nuclear magnetic resonance (NMR)
spectroscopy.
The three-dimensional structure of a protein or protein complex can provide
important information about its biological function. For decades, X-ray
crystallography has been the preferred method for analysis of protein structure.
However, many proteins are difficult to crystallize and achieve membrane protein
co-crystallization. Cryo-EM is especially suitable to obtain large protein complexes
and displays multiple conformation. Over the past several decades, researchers in
this area had made progress steadily, improving resolution of cryo EM and
expanding its biocompatibility.
Cryo-EM 3D reconstruction technology, X-ray crystallography and NMR (nuclear
magnetic resonance) technology are referred to the three main research methods
in structural biology. The main methods for three-dimensional structural analysis
by using cryo electron microscopy technique are: single particle analysis method,
electron tomography imaging method and electron crystallography.
Although the theoretical system have been established for ten years, but the
technology is not developed enough, resolution is not up to standard, and the
lowest temperature also can not meet the requirements. Many restrictions
hindered the pace of the development of this technology. Only the overall
conformation of vague virus can be observed.
In recent years, with the development of physics, enhancement of electron
microscopy equipment, and especial application of direct electron detectors in
Cryo TEM, cryo-EM 3D reconstruction technique is making an important
breakthrough in analyzing the structure of biological macromolecules and their
complexes in atomic resolution.
A landmark work is the 3.4 A resolution structure of ion channel membrane
protein TRPV1, which plays an important role in pain and thermal perception by
cryo-EM single particle analytical method.
The high resolution cryo EM 3D reconstruction bypasses the bottleneck of X-ray
crystallography in protein crystallization, which accounts for dominant position in
the field of structural biology, opening the door to directly use cryo EM Technology
Analysis of membrane proteins and super molecular complex.
Tags: electron microscope, protein, cryo-EM, X-ray crystallography
Source from: http://creative-biostructure.kinja.com/the-rise-of-the-low-
temperature-electron-microscope-1785674967?rev=1472009044119.
