Nobel Prize in Chemistry 2012: Smart Receptors On Cell Surfaces

Nobel Prize in Chemistry 2012: Smart Receptors On Cell Surfaces

  9:32:00 AM    Science Lover

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The Royal Swedish Academy of Sciences has decided to award the Nobel Prize in Chemistry for 2012 to Robert J. Lefkowitz Howard Hughes Medical Institute and Duke University Medical Center and Brian K. Kobilka Stanford University School of Medicine "for studies of G-protein-coupled receptors."

The seven-transmembrane α-helix structure of a 
G-protein-coupled receptor. (Credit: By Bensaccount at 
en.wikipedia [Public domain], from Wikimedia Commons)

Your body is a fine-tuned system of interactions between billions of cells. Each cell has tiny receptors that enable it to sense its environment, so it can adapt to new situtations. Robert Lefkowitz and Brian Kobilka are awarded the 2012 Nobel Prize in Chemistry for groundbreaking discoveries that reveal the inner workings of an important family of such receptors: G-protein-coupled receptors.

For a long time, it remained a mystery how cells could sense their environment. Scientists knew that hormones such as adrenalin had powerful effects: increasing blood pressure and making the heart beat faster. They suspected that cell surfaces contained some kind of recipient for hormones. But what these receptors actually consisted of and how they worked remained obscured for most of the 20th Century.

Lefkowitz started to use radioactivity in 1968 in order to trace cells' receptors. He attached an iodine isotope to various hormones, and thanks to the radiation, he managed to unveil several receptors, among those a receptor for adrenalin: β-adrenergic receptor. His team of researchers extracted the receptor from its hiding place in the cell wall and gained an initial understanding of how it works.

The team achieved its next big step during the 1980s. The newly recruited Kobilka accepted the challenge to isolate the gene that codes for the β-adrenergic receptor from the gigantic human genome. His creative approach allowed him to attain his goal. When the researchers analyzed the gene, they discovered that the receptor was similar to one in the eye that captures light. They realized that there is a whole family of receptors that look alike and function in the same manner.

Today this family is referred to as G-protein-coupled receptors. About a thousand genes code for such receptors, for example, for light, flavour, odour, adrenalin, histamine, dopamine and serotonin. About half of all medications achieve their effect through G-protein-coupled receptors.

The studies by Lefkowitz and Kobilka are crucial for understanding how G-protein-coupled receptors function. Furthermore, in 2011, Kobilka achieved another break-through; he and his research team captured an image of the β-adrenergic receptor at the exact moment that it is activated by a hormone and sends a signal into the cell. This image is a molecular masterpiece -- the result of decades of research.

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2010 Nobel Prize in Chemistry: Creating Complex Carbon-Based Molecules Using Palladium

2010 Nobel Prize in Chemistry: Creating Complex Carbon-Based Molecules Using Palladium

  12:06:00 AM    Science Lover

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The Royal Swedish Academy of Sciences has awarded the Nobel Prize in Chemistry for 2010 to Richard F. Heck, Ei-ichi Negishi and Akira Suzuki for developing new ways of linking carbon atoms together that has allowed scientists to make medicines and better electronics.

New ways of linking carbon atoms together has allowed scientists to make medicines and better electronics. (Credit: iStockphoto/Liang Zhang)

American citizen Richard F. Heck, 79, of the University of Delaware in Newark, Delaware, Japanese citizens Akira Suzuki, 80, of Hokkaido University in Sapporo, Japan, and Ei-Ichi Negishi, 75, of Purdue University in West Lafayette, Indiana, will share the 10 million Swedish crowns ($1.5 million) award for their development of "palladium-catalyzed cross couplings in organic systems."

Carbon, the atom that is the backbone of molecules in living organisms, is usually very stable and it can be difficult in the laboratory chemically to synthesize large molecules containing carbon. In the Heck reaction, Negishi reaction and Suzuki reaction, carbon atoms meet on a palladium atom, which acts as a catalyst. The carbon atoms attach to the palladium atom and are thus positioned close enough to each other for chemical reactions to start. This allows chemists to synthesize large, complex carbon-containing molecules.

The Academy said it's a "precise and efficient" tool that is used by researchers worldwide, "as well as in the commercial production of for example pharmaceuticals and molecules used in the electronics industry."

Great art in a test tube

Organic chemistry has developed into an art form where scientists produce marvelous chemical creations in their test tubes. Humankind benefits from this in the form of medicines, ever-more precise electronics and advanced technological materials. The Nobel Prize in Chemistry 2010 awards one of the most sophisticated tools available to chemists today.

This year's Nobel Prize in Chemistry is awarded to Richard F. Heck, Ei-ichi Negishi and Akira Suzuki for the development of palladium-catalyzed cross coupling. This chemical tool has vastly improved the possibilities for chemists to create sophisticated chemicals -- for example, carbon-based molecules as complex as those created by nature itself.

Carbon-based (organic) chemistry is the basis of life and is responsible for numerous fascinating natural phenomena: colour in flowers, snake poison and bacteria killing substances such as penicillin. Organic chemistry has allowed man to build on nature's chemistry; making use of carbon's ability to provide a stable skeleton for functional molecules. This has yielded new medicines and revolutionary materials such as plastics.

In order to create these complex chemicals, chemists need to be able to join carbon atoms together. However, carbon is stable and carbon atoms do not easily react with one another. The first methods used by chemists to bind carbon atoms together were therefore based upon various techniques for rendering carbon more reactive. Such methods worked when creating simple molecules, but when synthesizing more complex molecules chemists ended up with too many unwanted by-products in their test tubes.

Palladium-catalyzed cross coupling solved that problem and provided chemists with a more precise and efficient tool to work with. In the Heck reaction, Negishi reaction and Suzuki reaction, carbon atoms meet on a palladium atom, whereupon their proximity to one another kick-starts the chemical reaction.

Palladium-catalyzed cross coupling is used in research worldwide, as well as in the commercial production of for example pharmaceuticals and molecules used in the electronics industry.

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