Improved technique determines structure in membrane proteinsAugust 18, 2008CHAMPAIGN, Ill. - Understanding the form and function of certain proteins in the human body is becoming faster and easier, thanks to the work of researchers at the University of Illinois. By combining custom-built spectrometers, novel probe designs and faster pulse sequences, a team led by Illinois chemistry professor Chad Rienstra has developed unique capabilities for probing protein chemistry and structure through the use of solid-state nuclear magnetic resonance spectroscopy. The researchers' recent results represent significant progress toward atomic-scale resolution of protein structure by solid-state NMR spectroscopy. The technique can be applied to a large range of membrane proteins and fibrils, which, because they are not water-soluble, are often not amenable to more conventional solution NMR spectroscopy or X-ray crystallography.
"In our experiments, we explore couplings between atoms in proteins," Rienstra said. "Our goal is to translate genomic information into high-resolution structural information, and thereby be able to better understand the function of the proteins." Solid-state NMR spectroscopy relaxes the need for solubility of the sample. In solution NMR spectroscopy, molecules are allowed to tumble randomly in the magnetic field. In solid-state NMR spectroscopy, molecules are immobilized within a small cylinder called a rotor. The rotor is then spun at high speed in the magnetic field. "With increased speed and sensitivity, we can obtain very high resolution spectra," Rienstra said. "And, because we can resolve thousands of signals at a time - one for each atom in the sample - we can determine the structure of the entire protein." To improve sensitivity and accelerate data collection, Rienstra's group is developing smaller rotors that can be spun at rates exceeding 25,000 rotations per second. The faster rotation rate and smaller sample size allows the researchers to obtain more data in less time, and solve structure with just a few milligrams of protein. The determination of protein structure benefits not only from improvements in technology, but also from the researchers' novel approach to refining geometrical parameters. Structure determination is normally based upon distances between atoms. Rienstra discovered a way of measuring both the distance between atoms and their relative orientations with very high precision. "Using this technique, we can more precisely define the fragments of the molecule, and how they are oriented," Rienstra said. "That allows us to define protein features and determine structure at the atomic scale." University of Illinois at Urbana-Champaign | |||||||||||||||||||||
|
Related Spectroscopy Current Events and Spectroscopy News Articles Researchers shed new light on catalyzed reactions Rice University scientists on the hunt for a better way to clean up the stubborn pollutant TCE have created a method that lets them watch molecules break down on the surface of a catalyst as individual chemical bonds are formed and broken. New insight into the controls on a go-to enzyme Scientists at St. Jude Children's Research Hospital have gained new insights into regulation of one of the body's enzyme workhorses called calpains. Precise measurement of phenomenon advances solar cell understanding Researchers at Washington University in St. Louis have shed light on a basic process that could improve future solar cells. Electron pairs precede high-temperature superconductivity Like astronomers tweaking images to gain a more detailed glimpse of distant stars, physicists at the U.S. Department of Energy's (DOE) Brookhaven National Laboratory have found ways to sharpen images of the energy spectra in high-temperature superconductors - materials that carry electrical current effortlessly when cooled below a certain temperature. Study links primary insomnia to a neurochemical abnormality in young and middle-aged adults A study in the Nov. 1 issue of the journal Sleep is the first demonstration of a specific neurochemical abnormality in adults with primary insomnia, providing greater insight to the limited understanding of the condition's pathology. Secret Lives of Catalysts Revealed The first-ever glimpse of nanoscale catalysts in action could lead to improved pollution control and fuel cell technologies. Scientists from the U.S. Department of Energy's Lawrence Berkeley National Laboratory observed catalysts restructuring themselves in response to various gases swirling around them, like a chameleon changing its color to match its surroundings. Scientists Map Soils on an Extinct American Volcano Union County New Mexico is a landscape of striking diversity. Out of expansive rangelands rise sporadic yet majestic cinder cone volcanoes and mesas preserved by basalt, part of the Raton-Clayton Volcanic Field. Capulin volcano, formed approximately 62,000 years ago, is the youngest volcano in the field. Sensitive laser instrument could aid search for life on Mars Minuscule traces of cells can be detected in a mineral likely present on Mars, a new study shows. The results, obtained using a technique developed at the U.S. Department of Energy's Idaho National Laboratory, could help mission scientists choose Martian surface samples with the most promise for yielding signs of life. Gold nanostars outshine the competition Novel nanoparticles being tested at the National Institute of Standards and Technology (NIST) have researchers seeing stars. In a recent paper, NIST scientists used surface-enhanced Raman spectroscopy (SERS) to demonstrate that gold nanostars exhibit optical qualities that make them superior for chemical and biological sensing and imaging. Astronomers get best view yet of infant stars at feeding time Astronomers have used ESO's Very Large Telescope Interferometer to conduct the first high resolution survey that combines spectroscopy and interferometry on intermediate-mass infant stars. More Spectroscopy Current Events and Spectroscopy News Articles |
|||||||||||||||||||||
|
|||||||||||||||||||||
|
|||||||||||||||||||||