Mass Spectrometry (MR) and Nuclear Magnetic Resonance (NMR) are two very important fields of chemistry. The two fields had the hone to share the Nobel Prize in 2002. John B. Fenn, Koichi Tanaka, and Kurt Wuthrich have all had a part in further developing these methods of chemistry. Throughout this article it talks about why you should study biological macromolecules, how mass spectrometry is a method used to identify molecules, how each scientist contributed to the methods, and the NMR for biological macromolecules.
Studying biological macromolecules can help many people understand all living organisms. All living organisms contain the same type of large molecules and macromolecules. Everything in the cell is controlled by nucleic acids. Cells also have a variety of proteins that the cells use as leading actors. Every protein has a different function depending on its environment. Questions, such as, how can it be that man’s 30000-or-so genes code for hundreds of thousands of different proteins?
Have been brought up as a result too more and more organisms gene sequences are being mapped and researched. No one chemist can ever answer a question like this right off the top of their head so all chemists are always trying to gain more knowledge on proteins and how the function together with each other and with molecules in the cells. Mass spectrometry is a way for us to pinpoint a substance in sample on the groundwork of mass. The method of mass spectrometry has continued to be used by scientist on small and medium sized molecules.
There are many examples to where mass spectrometry is used such as foodstuff control, doping and drug tests. The usage of mass spectrometry for macromolecules has attracted many scientists. Even though macromolecules are large compared to normal sized molecules, they are still very small structures. To measure the mass of ions, proteins, is to stimulate them in a vacuum chamber where their TOF, time of flight, is measured. Many scientists have contributed to understanding the two fields of chemistry.
The two scientists that contributed to the field of mass spectrometry are John B. Fenn and Koichi Tanaka. John B. Fenn published two articles that made a breakthrough for mass spectrometry. The method could handle large molecule masses with high charges in the first article he published and in the second showed the use of the method on medium size whole proteins as well. Spraying the sample using an electrical field is how the ions are released and droplets are formed.
The method is now called electrospray ionization, ESI. Koichi Tanaka was also trying to contribute to the method while Fenn was except Tanaka was at the Japanese Shimadzu instrument company in Kyoto. He found an entirely different approach for the first critical stage. Tanaka learned that he could show protein molecules could be ionized using soft laser desorption (SLD). He was the first engineer to validate the ability of the laser technology to macromolecules. Mass spectrometry answers “what? and “how much? ” while NMR answers, “ What does it look like? ”. NMR (Nuclear Magnetic Resonance) is a method used to structure a picture of what a protein looks like. By using NMR someone can draw a three-dimensional picture of the molecule being studied. NMR is very limited by its low sensitivity: it requires incredible concentrated solutions. NMR is successful for small molecules but for large molecules it is hard. Kurt Wuthrich finally solved this problem.
He came up with the method of pairing each NMR signal with the right hydrogen nucleus in the macromolecules. Wuthrich call it sequential assignment. In 1985 is when Wuthrich showed the first complete determination of a protein structure. Today 15-20% of all the known protein structures have been determined with NMR. The structures of others have been found with X-ray crystallography. The most industrial use of NMR is in the search of small potential pharmaceutical molecules that can interact with a given biological macromolecule.
