Microscope trailblazers win 2017 Nobel prize for Chemistry

Share

In case you've not been following, this week has seen the announcements of the Nobel Prize for Medicine and Physics on Monday and Tuesday respectively.

Swiss national Dubochet added water.

Three researchers based in the US, United Kingdom and Switzerland won the Nobel Prize in Chemistry on Wednesday for developments in electron microscopy. The use of both techniques was, however, subject to limitations imposed by the nature of biomolecules.

Henderson was frustrated that x-ray crystallography, which requires samples to stay in rigid formations, wasn't representative of biomolecules' dynamic structures. And NMR worked for only a relatively small set of proteins.

The Nobel committee hailed the group's technology, saying it had "taken biochemistry into a new era".

By 1990, Henderson was able to capture a far more detailed model of bacteriorhodopsin - the same protein in his original image - using cryo-electron microscopy. And a reduction in the intensity of the beam means a substantial loss in contrast, and the image becomes fuzzy. "Liquid water evaporates in the electron microscope's vacuum, which makes the biomolecules collapse". Then the samples are pelted by a beam of radiation that can fry sensitive biomolecules.

Microscopes allow scientists to look at structures that can not be seen with the naked eye - but when these structures are very tiny, it is no longer possible to use rays of light to do the job because their wavelengths are not short enough.

This was in 1975.

A recently developed technique called cryo-electron microscopy creates 3D visualizations of biological molecules like proteins, DNA, and RNA, making them visible in ways previously thought impossible.

With these three discoveries, "the electron microscope's every nut and bolt have been optimised", according to the Nobel Foundation, but it's also the application of this technology that is important.

Hansson said the scientists were being recognized for what he described as "a cool method for imaging the molecules of life". To get the sharpest images he travelled to the best electron microscopes in the world. The solution he envisaged was to freeze water rapidly so that instead of solidifying into a crystalline solid, it freezes into a disordered state, which is like a glass. But water freezes at low temperatures, creating crystals that alter natural bioarchitecture. They swapped water with a sugar cocktail, which could withstand the vacuum and systematically tweaked the settings of their microscope to limit the damage caused by the electrons.

"Now, we need to apply this to look at larger complexes to understand how these different molecular machines work", Subramaniam says. The technique is used in cryo-EM.

He explained that cryo-electron microscopy emerged back in the 1980s, and has been actively developing over the recent years due to the improvement in tool and computing platforms, including supercomputers.

Share