Electronic cryomicroscopy: a photographer of invisible beings in Mendoza

[Inkriql]

It is that photographing invisible beings can sound like science fiction or illusionism. However, Joachim Frank is a renowned German scientist who in 2017 won the Nobel Prize in Chemistry as a pioneer of the technique of electronic cryomicroscopy. And his studies are serious, so much that metaphor through, we could say that his technique works something like the "3D camera with more megapixels that exists, to capture images of biological structures of infinitesimal size".

Joachim Frank will arrive in Mendoza to participate as lecturer of the II Symposium on Translational Medicine, organized by the Faculties of Medical Sciences and Exact and Natural Sciences of the UNCuyo.

How to photograph something that is not seen

For in science, observing things that are not visible to the naked eye, invisible to the eyes of ordinary people, is a long-standing custom. The electron microscope, without going any further, is just a hundred years old.

But before Frank and his revolutionary technique, there was one important limitation: electronic microscopes required observation objects to be presented in vacuum. Therefore, it was not possible to study biological molecules in their natural environment. Then, Frank formulated a technique that would take biochemistry to a new era.

Using advances from two scientists with whom he would later share the Nobel, Jacques Dubochet and Richard Henderson, Frank agreed to solve this problem by freezing the sample to be analyzed by means of gases such as liquid nitrogen or propane, with care that they will form ice crystals that could distort the image. Thus it was possible to obtain a capture: frozen biomolecules in full movement, with which it is possible to visualize processes that had never before been seen. Then, Frank gave a new twist to the discoveries of its partners (yes, science is an associated and solidary task) and developed a computer tool to enhance the existing observation instruments.

It happens that the electron microscopes have a great power of resolution, that allows to observe in detail a cell and its content, even up to the strands of DNA. Overcoming that instance, they could go even further, to the point of seeing the atoms that make up a protein. The problem is that always the images at that level of detail are affected by "noise". This is where Frank rubbed the lamp and designed an image processing method that allows to align and averaged thousands of very blurry 2D images of individual molecules, and transform them into three-dimensional atomic resolution structures, thus achieving that artificial intelligence can even learn to deduce how are the hidden faces of a two-dimensional image and complete them. What do we have opposite, then? Nothing more and nothing less than, practically, a virtual tour of a biomolecule. Thus, a researcher can move as a spy, and in the case of a virus for example, it is possible to understand key aspects of its life cycle, how is the binding to receptors on the surface of cells that become infected, the mechanics of transfer of the cell membrane, how the replication works, assembly and exit of the new viral particles of the host cell, etc. And you know ... knowing the enemy to the detriment multiply the possibilities of preventing or generating vaccines or antiviral drugs efficiently.

The electronic cryomicroscopy is the result of an 11-year research work by Joachim Frank and a group of scientists from different parts of the world, who produce knowledge in the best way that can be done: in a collaborative and transdisciplinary way. Given this, the "translationality of science" is nothing more than "up the ante". In the case of medicine, the translational is given by the association of efforts to form networks that allow the rapid translation of findings of basic sciences (biology, biochemistry, physics, mathematics, etc.) into better preventive and curative treatments.

The Second International Symposium on Translational Medicine will be held at the Faculty of Medical Sciences of the UNCuyo, on March 7 and 8, calling a large group of national and international speakers, who will offer 30 talks around the axes Oncology , Cardiology, Immunology, Fertility, Biophysics and Nanotechnology, and Imaging.

In the opportunity, the doctors Joachim Frank, Roland Mertelsmann and Christoph Borner will be distinguished by the UNCuyo with the title of Doctor Honoris Causa.