The Nobel Prize in Chemistry 2015 was awarded jointly to Tomas Lindahl (Sweden), Paul Modrich (USA) and Aziz Sancar (USA) “for mechanistic studies of DNA repair”.
WHAT IS DNA ?
DNA, or deoxyribonucleic acid, is the hereditary material in humans and almost all other organisms. Nearly every cell in a person’s body has the same DNA. Most DNA is located in the cell nucleus (where it is called nuclear DNA), but a small amount of DNA can also be found in the mitochondria (where it is called mitochondrial DNA or mtDNA).
DNA stores biological information. The DNA backbone is resistant to cleavage, and both strands of the double-stranded structure store the same biological information. Biological information is replicated as the two strands are separated. A significant portion of DNA (more than 98% for humans) is non-coding, meaning that these sections do not serve as patterns for protein sequences.
THEIR LATEST DISCOVERY:
The Nobel Prize in Chemistry 2015 is awarded to Tomas Lindahl, Paul Modrich and Aziz Sancar for having mapped, at a molecular level, how cells repair damaged DNA and safeguard the genetic information. Their work has provided fundamental knowledge of how a living cell functions and is, for instance, used for the development of new cancer treatments.
Each day our DNA is damaged by UV radiation, free radicals and other carcinogenic substances, but even without such external attacks, a DNA molecule is inherently unstable. Thousands of spontaneous changes to a cell’s genome occur on a daily basis. Furthermore, defects can also arise when DNA is copied during cell division, a process that occurs several million times every day in the human body.
The reason our genetic material does not disintegrate into complete chemical chaos is that a host of molecular systems continuously monitor and repair DNA. The Nobel Prize in Chemistry 2015 awards three pioneering scientists who have mapped how several of these repair systems function at a detailed molecular level.
In the early 1970s, scientists believed that DNA was an extremely stable molecule, but Tomas Lindahl demonstrated that DNA decays at a rate that ought to have made the development of life on Earth impossible. This insight led him to discover a molecular machinery, base excision repair, which constantly counteracts the collapse of our DNA.
Aziz Sancar has mapped nucleotide excision repair, the mechanism that cells use to repair UV damage to DNA. People born with defects in this repair system will develop skin cancer if they are exposed to sunlight. The cell also utilises nucleotide excision repair to correct defects caused by mutagenic substances, among other things.
Paul Modrich has demonstrated how the cell corrects errors that occur when DNA is replicated during cell division. This mechanism, mismatch repair, reduces the error frequency during DNA replication by about a thousandfold. Congenital defects in mismatch repair are known, for example, to cause a hereditary variant of colon cancer.
The Nobel Laureates in Chemistry 2015 have provided fundamental insights into how cells function, knowledge that can be used, for instance, in the development of new cancer treatments.
Also read: 2015 Noble Prize in Medicine
Youngest Chemistry Laureate
To date, the youngest Nobel Laureate in Chemistry is Frédéric Joliot, who was 35 years old when he was awarded the Chemistry Prize in 1935, together with his wife, Irène Joliot-Curie.
Oldest Chemistry Laureate
The oldest Nobel Laureate in Chemistry to date is John B. Fenn, who was 85 years old when he was awarded the Chemistry Prize in 2002.
Female Nobel Laureates in Chemistry
Of the 168 individuals awarded the Nobel Prize in Chemistry, four are women so far. Two of these four women, Marie Curie and Dorothy Crowfoot Hodgkin, were awarded with unshared Chemistry Prizes.
1911 – Marie Curie (also awarded the 1903 Nobel Prize in Physics)
1935 – Irène Joliot-Curie (daughter of Marie Curie and wife to Frédéric Joliot)
1964 – Dorothy Crowfoot Hodgkin
2009 – Ada Yonath
Also read: 2015 Noble Prize in Physics
LIST OF NOBLE PRIZE WINNERS IN CHEMISTRY
2014: Eric Betzig, Stefan W. Hell and William E. Moerner “for the development of super-resolved fluorescence microscopy”
2013: Martin Karplus, Michael Levitt and Arieh Warshel “for the development of multiscale models for complex chemical systems”
2012: Robert J. Lefkowitz and Brian K. Kobilka “for studies of G-protein-coupled receptors”
2011: Dan Shechtman “for the discovery of quasicrystals”
2010: Richard F. Heck, Ei-ichi Negishi and Akira Suzuki “for palladium-catalyzed cross couplings in organic synthesis”
2009: Venkatraman Ramakrishnan, Thomas A. Steitz and Ada E. Yonath “for studies of the structure and function of the ribosome”
2008: Osamu Shimomura, Martin Chalfie and Roger Y. Tsien “for the discovery and development of the green fluorescent protein, GFP”
2007: Gerhard Ertl “for his studies of chemical processes on solid surfaces”
2006: Roger D. Kornberg “for his studies of the molecular basis of eukaryotic transcription”
2005: Yves Chauvin, Robert H. Grubbs and Richard R. Schrock “for the development of the metathesis method in organic synthesis”
2004: Aaron Ciechanover, Avram Hershko and Irwin Rose “for the discovery of ubiquitin-mediated protein degradation”
Nobel Prizes in Chemistry was not awarded on eight occasions: in 1916, 1917, 1919, 1924, 1933, 1940, 1941 and 1942.