An improved method of visualizing molecules made it possible to obtain the clearest images and to make out individual atoms in a protein for the first time. Scientists have achieved atomic resolution using cryogenic electron microscopy (cryo-EM). Now they will be able to consider and study the work of proteins that cannot be seen by other methods, such as X-ray crystallography.
This breakthrough will consolidate the position of cryo-EM as the dominant tool for studying proteins, scientists say. In the future, this will lead to the creation of better medicines with fewer side effects.
“This is a really important milestone. We have nothing more to overcome – this was the last barrier of resolution ”Holger Stark, biochemist at the Institute of Biophysical Chemistry. Planck in Gottingen (Germany)
In electron cryomicroscopy, samples are examined at cryogenic temperatures. The first resolution improvements using this method began back in 2013. But then this only led to the fact that the samples could be seen in as much detail as with x-ray crystallography.
Subsequent advances in hardware and software have led to major improvements in the resolution of cryo-EM structures. But scientists had to rely heavily on X-ray crystallography to obtain atomic resolution structures. Researchers could spend from several months to several years for protein crystallization. Cryo-EM can be used instantly; long preparations are not needed for experiments – just a sample in a special solution.
As the researchers note, the spatial structure of complex biological molecules or viruses is usually investigated by x-ray crystallography. This method requires the production of high-quality crystals, which can also be destroyed by radiation. In addition, crystals that are absolutely free from defects, as a rule, cannot be grown.