Nordic Life Science 1
THE NOBEL PRIZE // CHEMISTRY “I fell in love with
organic chemistry when I took the course in college as a premed requirement. After that course, I changed my major to chemistry and the rest is history.” T HE OTHER TWO Laureates, Morten Meldal of Denmark and K. Barry Sharpless of the U.S., laid the foundations for what today is known as click chemistry, a functional form of chemistry in which molecular building blocks snap together quickly and efficiently; think Lego for chemists. Carolyn Bertozzi took click chemistry to a new dimension when she started to utilize it in living organisms to map cells. This class of chemical reactions is called bioorthogonal chemistry and before Bertozzi’s development of them 22 years ago, researchers risked disturbing natural processes when observing molecules and their interactions in living beings. “I have a longstanding interest in glycoscience, and unmet needs in that field motivated my lab to invent bioorthogonal chemistries,” says Carolyn Bertozzi. The problem when working with living cells is that copper, used by Meldal and Sharpless in the click chemistry, is toxic. However Bertozzi found that it had been shown in 1961 that azides and alkynes can react in an almost explosive manner, without the help of copper, if the alkyne is forced into a ring-shaped chemical structure. The strain creates so much energy that the reaction runs smoothly. It worked, and in 2004 she published her copper-free click reaction, called the strain-promoted alkyne-azide cycloaddition. “In vivo imaging of cell surface glycans was the original application that drove the invention of bioorthogonal chemistry,” describes Bertozzi. Other ther labs have since used the technique to image proteins, lipids, nucleic acids and many other biomolecules and post translational modifications. Targeting treatments within molecules Bioorthogonal reactions allow researchers and clinicians to work without disrupting a molecular reaction’s normal routine or nearby healthy cells, creating opportunities for targeting treatments within molecules. Gunnar C. Hansson, Professor at the Department of Medical Biochemistry and Cell Biology at the University of Gothenburg, says that his research group as well as others involved in medical research have made great use of Carolyn Bertozzi’s discovery. “We have for example learned that the some tenths of a millimeter thick protective mucus layer in the large intestine that keeps bacteria away from us is renewed within one hour. Incredibly, much faster than we could imagine,” he explains to NLS. NORDIC LIFE SCIENCE 23