The Nobel Prize in Chemistry for 2017 was awarded to Jacques Dubochet, Joachim Frank and Richard Henderson

 for developing cryo-electron microscopy for the high-resolution structure determination of biomolecules in solution.

The Royal Swedish Academy of Sciences awarded the 2017 Nobel prize in Chemistry jointly to Jacques Dubochet (University of Lausanne, Switzerland), Joachim Frank (Columbia University, New York, USA) and Richard Henderson (MRC Laboratory of Molecular Biology, Cambridge, UK). 

Each of this year's laureates contributed with a crucial part of cryo-electron microscopy. Electron microscopy, a technique invented in the 1930's, was always seen as a technique to analyze and study dead matter. The birth of cryo-electron microscopy started in 1975 with Richard Henderson when, he created a 3D render of bacteriorhodopsin’s structure with a resolution of 7 Ångström. Despite being very impressive was still far from the resolution of X-ray crystallography, 3 Ångström. Electron Microscopy continued to evolve and in 1990, Richard Henderson published the structure of bacteriorhodopsin with atomic resolution. However, this technique had a major problem, at the time it could only be applied to proteins that were evenly packed in the cell membrane.

The application of cryo-electron microscopy to randomly scattered proteins was the problem that Joachim Frank was tackling. In 1975, Frank proposed a theoretical method which could be used to combine 2D images from an electron microscope into a detailed 3D model. This method relied on using a computer to compile many 2D traces of the protein and then assemble similar traces into a high-resolution image. The next step was to calculate how these 2D images related to each other and stacked together to produce a 3D model of the protein. By the mid 1980’s all the algorithms required were complete and put to the test when Frank published a 3D model of a ribosome.

However, there was still one major obstacle to overcome for cryo-electron microscopy to be a viable technique, keeping the protein samples in solution. Electron microscopy requires a vacuum and in a vacuum, water instantly evaporates, causing the structure of most biomolecules to collapse.

Jacques Dubochet started to tackle this problem in 1978, when he was hired by the European Molecular Biology Laboratory in Heidelberg. Dubochet had experimented with coating samples in a glucose solution to protect the samples but this had limited applications and success. Other researchers had tried freezing the samples but the ice crystals disrupted the electron beam from the electron microscope and the images were not acceptable. Dubochet’s group experimented with several methods of rapid cooling until in 1982, they managed to vitrify water by cooling it with ethane that was cooled by liquid nitrogen at -196◦ C. In 1984 the first images using this technique were published.

Even though all the pieces had come together, the resolution of electron microscopy still had to come a long way to achieve atomic resolution and so it did until in 2013 when it was achieved.

Their contribution to the development of cryo-electron microscopy radically increased the resolution that electron microscopy could achieve and allowed scientists to observe biomolecules with an atomic resolution. This was a major step forward in Biochemistry as molecules could now be observed mid movement and also allowed scientists to observer biomolecules that were extremely hard to crystallise such as membrane proteins. You can learn more about the amazing contribution of these 3 scientists through the Popular Science Background document from the Nobel Prize's official website.

You can watch the announcement of this year's Chemistry laureates on the video below:

For more information on this year's Chemistry laureates you can check the offical Nobel Prize website.