The 2017 Nobel Prize for Chemistry has been won by three scientists credited with development of cryo-electron microscopy technique that allows study of biomolecules not visible through previously available microscopic techniques.
Jacques Dubochet is based at University of Lausanne, Switzerland; Joachim Frank at Columbia University, USA; and Richard Henderson at Molecular Biology Laboratory at Cambridge, UK.
From conventional to electron microscopy
Tiny atomic and molecular structures invisible to the human eye become visible through conventional microscopes. But beyond a certain limit the latter become useless since even the shortest wavelength in rays of light isn’t short enough to ensure visibility at such a small-scale.
For such structures, a technique known as transmission electron microscopy (TEM) is frequently employed. It also has its shortcomings as the beam of electrons and vacuum used in it affect biomolecules under study, rendering the findings inaccurate.
With cryo-electron microscopy, researchers can now freeze biomolecules to be studied in the middle of their movement and visualise their structure in details unavailable through existing technology.
Nobel laureates’ contributions
Using an electron microscope, Richard Henderson generated a three-dimensional image of a protein at atomic resolution for the first time in 1990. Back then, it was a breakthrough development.
Joachim Frank’s work made the technology more generally applicable. Between 1975 and 1986, he developed an image processing method in which the electron microscope’s fuzzy two-dimensional images were analysed and merged to reveal a sharp three-dimensional structure.
Jacques Dubochet’s contribution was a technique that solved problems related to evaporation of water in electron microscope’s vacuum, which affected study of water-soluble biomolecules. His technique cooled water so rapidly that it solidified before water molecules could change their form into that of ice. This allowed biomolecules under observation to retain their natural shape even in a vacuum.
The desired atomic resolution for the technique was reached in 2013, and researchers have since been using it to produce three-dimensional structures of biomolecules.
In the past few years, scientists have used the technique to generate images of proteins that cause antibiotic resistance and the surface of the Zika virus. In fact, it was because of the cryo-electron imaging technique that researchers were able to determine the exact shape of the Zika virus.
The technique developed by the Nobel laureates has enabled researchers to generate detailed images of complex biomolecular structures and processes. It promises to revolutionise study of biomolecules and enhance scientists understanding of various diseases and ability to develop more effective cures.