- Koichi Tanaka
name = Koichi Tanaka
image_size = 180px
birth_date = birth date and age|1959|8|3
birth_place = Toyama, Japan
Soft laser desorption
Nobel Prize for Chemistry(2002)
Koichi Tanaka (田中 耕一 "Tanaka Kōichi", born
August 3, 1959) is a Japanese scientist who won the Nobel Prize in Chemistryin 2002 for developing a novel method for mass spectrometric analyses of biological macromolecules. [cite journal |author=Tanaka, K.; Waki, H.; Ido, Y.; Akita, S.; Yoshida, Y.; Yoshida, T. |title=Protein and Polymer Analyses up to m/z 100 000 by Laser Ionization Time-of flight Mass Spectrometry |journal=Rapid Commun Mass Spectrom |volume=2 |issue=20 |pages=151–3 |year=1988|issn= |doi=10.1002/rcm.1290020802] [ cite web|url=http://www.jce.divched.org/JCEWWW/Features/eChemists/document.php?chemid=62 |title=Biographical Snapshots of Famous Women and Minority Chemists: Snapshot |accessdate=2008-08-18 ]
Tanaka was born and raised in Toyama, Japan. In 1983, he graduated from
Tohoku Universitywith a bachelor's degree in engineering. As of 2008, he is the only person without a post-bachelor's degree to have won a Nobel Prize in a scientific field. After graduation, he joined Shimadzu Corporation, where he engaged in the development of mass spectrometers.
For mass spectrometry analyses of a macromolecule, such as a
protein, the analyte must be ionized and vaporized by laserirradiation. The problem is that the direct irradiation of an intense laser pulse on a macromolecule causes cleavage of the analyte into tiny fragments and the loss of its structure. In February 1985, Tanaka found that by using a mixture of ultra fine metal powder in glycerolas a matrix, an analyte can be ionized without losing its structure. His work was filed as a patent application in 1985, and after the patent application was made public reported at the Annual Conference of the Mass Spectrometry Society of Japan held in Kyoto, Japan, in May 1987 and became known as soft laser desorption(SLD). [cite web | last =Markides | first =K | authorlink = | coauthors =Gräslund, A | title =Advanced information on the Nobel Prize in Chemistry 2002 | work = | publisher = | date = | url =http://nobelprize.org/chemistry/laureates/2002/chemadv02.pdf | format =PDF | doi = | accessdate = ]
However, there was some criticism about his winning the prize, saying that contribution by two German scientists,
Franz Hillenkampand Michael Karaswas also big enough not to be dismissed, and therefore they should also be included as prize winners. This is because they first reported in 1985 a method, with higher sensitivity using a small organic compoundas a matrix, that they named Matrix-Assisted Laser Desorption/Ionization(MALDI). [cite journal |author=Karas, M.; Bachmann, D.; Hillenkamp, F. |title=Influence of the Wavelength in High-Irradiance Ultraviolet Laser Desorption Mass Spectrometry of Organic Molecules |journal=Anal. Chem. |volume=57 |issue= |pages=2935–9 |year=1985|issn= |doi=10.1021/ac00291a042] Also Tanaka's SLD is not used currently for biomolecules analysis, meanwhile MALDI is widely used in mass spectrometry research laboratories. But while MALDI was developed prior to SLD, it was not used to ionize proteins until after Tanaka's report. [cite journal |author=Karas M, Hillenkamp F |title=Laser desorption ionization of proteins with molecular masses exceeding 10,000 daltons |journal=Anal. Chem. |volume=60 |issue=20 |pages=2299–301 |year=1988 |pmid=3239801 |url=http://www.klinikum.uni-muenster.de/institute/impb/research/hillenkamp/ac_60_1988_2299.pdf |doi=10.1021/ac00171a028]
* [http://nobelprize.org/chemistry/laureates/2002/index.html The Nobel Prize in Chemistry 2002]
* [http://www1.shimadzu.com/about/nobel/index.html Nobel Prize Announcement] ( [http://www.shimadzu.com/ Shimadzu Corporation] )
* [http://www.jce.divched.org/JCEWWW/Features/eChemists/document.php?chemid=62 Biographical snapshots: Koichi Tanaka,] "Journal of Chemical Education" web site.
Wikimedia Foundation. 2010.