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Wednesday, October 10, 2012

Ladies and Gentleman, the winners have been announced!

Robert J. Lefkowitz (left) and Brian K. Kobilka (right)
At 2:30AM this morning in California, the recipients of the Nobel Prize in Chemistry were called and informed of their accomplishments. Robert J. Lefkowitz, 69, and Brian K. Kobilka, 57, have discovered the molecular workings and structures of G protein-coupled receptors (GPCRs). GPCRs are a family of proteins that have been discovered to be the transmitters of critical biological messages for functions such as vision, smell, taste, and neurotransmission.

The two men set out on their scientific journey in an attempt to understand the biological processes that occur during a body’s production of stress hormones, such as adrenaline. Science already uncovered what happens to a person when the hormones are produced; a receptor is bound by the hormone and then a person experiences focused vision, quickened breathing, diverting blood from the less important body systems etc. The groundbreaking aspect of Lefkowitz and Kobilka’s findings is that the nature of the receptors for these hormones are now known.

Lefkowitz first traced the signaling of these receptors in the 1970s with radioactive blocking agents attached to hormones. By marking the hormones, Lefkowitz was able to follow where they attached in the body and observe the activities of the receptors they attached to. With much effort, Dr. Lefkowitz was able to identify the receptor proteins and prove they were specific molecules.

In the 1980s, Lefkowitz’s group at Duke University, which Kobilka was a part of, found the gene that actually produced one of the protein receptors. The group saw that the shape of the protein had many long spirals that wove through the cell membrane exactly seven times.

3D image of rhodopsin.
Realizing that the receptor he discovered had the same characteristic seven helicies as another receptor that had been found in the retina, in this case the light receptor rhodopsin, Lefkowitz and his team set out to find several other similar receptors that were found to be in a family of receptors, called the G protein-coupled receptors. Today, about a thousand of these GPCRs are known. They reside on the surface of cells and react to a host of hormones and neurotransmitters. Dr. Kobilka moved to Stanford and progressed to determine the three-dimensional structure of the GPCRs, which involved the utilization of x-ray crystallography.
“We hope by knowing the three-dimensional structure we might be able to develop more selective drugs and more effective drugs,” Dr. Kobilka said. The ultimate goal with all this new information is to refine drug design. Many drug molecules attach to cells, not only at the intended target, but also to other receptors.  This may help eliminate those unwanted side effects that one experiences when taking certain drugs.

Monday, October 1, 2012

As some of you may have heard, there are some curious things happening on Mars. To be specific, there is a robot named Curiosity cruising around the red planet as we speak, and he is packing some heat, literally.

Picture of Curiosity while he was waiting
to be sent on his mission to Mars.

On our friend Curiosity, who is the size of a car and runs on nuclear power, there is a device that turns rocks into dust for his analysis on Mars. The rock-vaporizing laser, named ChemCam, has a range of 25 feet and can identify elements in the rock gas. Scientists are hoping that ChemCam finds rock vapors that have traces of carbon in order to further research efforts.

Another tool Curiosity has on his belt isn’t something you can buy at the Home Depot, because a team that consists of scientists and engineers at NASA’s Goddard Space Flight Center, University of Paris, Jet Propulsion Laboratories, and Honeybee Robotics created this microwave-sized instrument. SAM (Sample Analysis at Mars) has 74 cups to use for studying ground-up rocks that will be heated to 1800 degrees, and then examined by three different instruments (Quadrupole Mass Spectrometer, Gas Chromatograph, and Tunable Laser Spectrometer) in order to identify the compounds on Mars, and hopefully find organic materials.

Now, you may be thinking, “Kayte, NASA already sent up two Viking landers in 1976 to examine the surface of Mars for organics.” What SAM does, that the Viking landers didn’t do in the 70’s, is heat up the examined rocks to temperatures hotter than the Vikings could. This intense heat destroys perchlorates, which are believed to destroy organics during the increase of its environment’s temperature, before they get a chance to eat up the vital organics Curiosity is looking for. SAM also has nine cups that utilize a chemical solvent that gives way for SAM to examine rocks at lower temperatures.

A cartoon view of where the three different
instruments are located within SAM.
Such altered methods of examining rock compositions will hopefully assist scientists in answering three main questions while Curiosity is checking out Mars. These questions can be found on the SAM Instrumentation description on the NASA website, as well as a description of the systems and instruments contained within SAM’s capabilities.

The possibility of life on Mars is a concept that NASA is still trying to validate. With NASA’s hopes and dreams up on the red planet set within a robot named Curiosity, we can only hope that his friends ChemCam and SAM can help him bring us answers that feed our interests in the possibility of a futuristic world on Mars.

Bring ‘em home Curiosity. Bring ‘em home.