Nobel Prize in Chemistry 2015
The Nobel Prize in Chemistry 2015 was awarded jointly to Tomas Lindahl, Paul Modrich and Aziz Sancar. The scientists have opened a new frontier in medicine by unveiling how the body repairs DNA mutations that can cause sickness and ageing. Their work led to the understanding of how the living cell functions, causes for several hereditary diseases, cancer development and ageing.
DNA (Deoxyribonucleic acid) is the chemical code for making and sustaining life. Throughout the lifetime our body cells divides, replicates for billions of times. During the division of cells error may occur in copying of code and it can cause the daughter cells to die or malfunction. DNA can also be damaged by UV radiation and other environmental factors. But there is a swarm of proteins designed to monitor the process and repair the damage.
Tomas Lindahl is a swedish-born British scientist and is presently working at Francis Crick Institute, London. Towards the end of 1960’s, many scientists considered DNA to be incredibly stable. But Lindahl has discovered that there were thousands of potentially devastating injuries to the genome every day even when the molecule is located in the cell’s protective environment. He also discovered that there is a molecular mechanism, base excision repair, to repair the damage caused to the DNA. Initially, he conducted the experiments with bacterial DNA. In 1996, he was managed to recreate the human DNA repair process in vitro.
Aziz Sancar is from the University of North Carolina. Human DNA can be disrupted due to environmental factors, such as UV radiation. Sancar noticed that bacteria exposed to deadly doses of UV could repair themselves if lit up blue light. He discovered an enzyme called photolyase that repairs UV-damaged DNA. He went on to identify enzymes that spot UV damage and then cut the DNA to remove the faulty genetic code. Later he mapped the equivalent repair process in humans.
Paul Modrich is from the Howard Hughes Medical Institute and Duke University School of Medicine. He has spent more than a decade in mapping out enzymes involved in what is called DNA mismatch repair – another way that DNA can be disrupted through faulty pairings of Cs, Gs, As, and Ts. Mismatch repair is a major process for protecting DNA. Mismatch repair can correct thousand errors that occur when the human genome is copied.
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