Forum for Science, Industry and Business

Sponsored by:     3M 
Search our Site:


New method for ’visualizing’ proteins


A newly established national biomedical center at Cornell University is reporting its first major advance: a new way of measuring, or "visualizing," proteins. The new technique will hasten the transformation of the human genome project’s blueprints of life into a comprehensive view of the biochemical and physiological circuitry that interconnect to form entire organisms.

The technique, which determines the structure of a protein by measuring the distances between atoms in the molecule at greater separations than previously possible, is an important development, says Jack Freed, professor of chemistry and chemical biology at Cornell, who is director of the National Biomedical Center for Advanced ESR Technology (ACERT), established at Cornell last year by the National Institutes of Health. "This is in the spirit of seeing the whole forest of the protein, whereas before we have been seeing the trees one after another," says Freed.

Freed and his collaborators, Hassane Mchaourab, professor of molecular physiology and biophysics at the Vanderbilt University School of Medicine, and Peter Borbat, associate director of ACERT, report on the new method for protein structure determination in JACS , the Journal of the American Chemical Society (May 22, 2002).

"This technique is potentially very powerful for the investigation of larger protein assemblies and membrane proteins," says Yeon-Kyun Shin, associate professor of biophysics at Iowa State University and a major user of the ACERT facility.

The new method for seeing the structure of the protein uses ESR (electron spin resonance), a technology for studying the bonds, structures, and molecular mechanisms of chemical and biological materials, such as membranes and proteins. Basically, the technique elucidates how molecules move, react and interact with one another. The protein studied for the JACS report, T4 Lysozyme, is one of the proteins of a bacteriophage, or virus, that is parasitic within a bacterium. The protein degrades the bacterial cell wall to enable the virus’s exit.

Previously, Freed’s group pioneered technology that enables ESR methods to unravel the complex dynamics of biosystems such as proteins and membranes. The research group has adapted this technology, dubbing it DQC (for double quantum coherence), to deliver pulses of microwave radiation in appropriate sequences in order to measure the distances between two spin labels. These are molecular subunits, each containing an unpaired electron, inserted at precise sites in the protein. DQC-ESR "interrogates" the spin labels for their weak interaction, the magnitude of which depends on the distance between them. By measuring such distances, the overall structure of the protein can be revealed.

Until now, protein structure has been determined primarily by two widely used methods: X-ray crystallography and nuclear magnetic resonance (NMR) spectroscopy. The X-ray method, however, requires crystallization of the protein, and as Freed explains, a protein is not just a single crystal or a frozen object but is in constant flexing and tumbling motion. NMR visualizes the molecule in its normal environment and is based on measuring many small distances between adjacent, or nearly adjacent, atoms, like going from tree to tree. The new technology reported in the JACS paper, which needs only very small amounts of protein, gives researchers a comprehensive view of a the molecule, "like being able to see the topology of the entire forest," says Mchaourab.

He notes that 30 percent of the proteins encoded by a genome and 50 percent of pharmaceutically important receptors are membrane-embedded proteins "that are not so easily studied by the two main structural techniques, X-ray crystallography and NMR."

In a larger context, the new technology will aid "the rush" to transform genome sequencing projects’ blueprints into broad views of protein function, says Mchaourab. "Central to this endeavor is structural biology that will transform these one-dimensional strings of DNA sequences into three-dimensional visual frameworks of how catalysis, ion conduction and energy transduction are carried out by proteins," he says. Structural biology and structural genomics are aimed at creating a catalog of the entire complement of unique proteins encoded by a genome.

Notes Mchaourab: "The ability of ACERT to transform this technology into a routine laboratory procedure will allow a whole new set of protein assays [testing and analysis] to emerge."

David Brand | EurekAlert!
Further information:

More articles from Life Sciences:

nachricht North and South Cooperation to Combat Tuberculosis
22.03.2018 | Universität Zürich

nachricht Researchers Discover New Anti-Cancer Protein
22.03.2018 | Universität Basel

All articles from Life Sciences >>>

The most recent press releases about innovation >>>

Die letzten 5 Focus-News des innovations-reports im Überblick:

Im Focus: Researchers Discover New Anti-Cancer Protein

An international team of researchers has discovered a new anti-cancer protein. The protein, called LHPP, prevents the uncontrolled proliferation of cancer cells in the liver. The researchers led by Prof. Michael N. Hall from the Biozentrum, University of Basel, report in “Nature” that LHPP can also serve as a biomarker for the diagnosis and prognosis of liver cancer.

The incidence of liver cancer, also known as hepatocellular carcinoma, is steadily increasing. In the last twenty years, the number of cases has almost doubled...

Im Focus: Researchers at Fraunhofer monitor re-entry of Chinese space station Tiangong-1

In just a few weeks from now, the Chinese space station Tiangong-1 will re-enter the Earth's atmosphere where it will to a large extent burn up. It is possible that some debris will reach the Earth's surface. Tiangong-1 is orbiting the Earth uncontrolled at a speed of approx. 29,000 km/h.Currently the prognosis relating to the time of impact currently lies within a window of several days. The scientists at Fraunhofer FHR have already been monitoring Tiangong-1 for a number of weeks with their TIRA system, one of the most powerful space observation radars in the world, with a view to supporting the German Space Situational Awareness Center and the ESA with their re-entry forecasts.

Following the loss of radio contact with Tiangong-1 in 2016 and due to the low orbital height, it is now inevitable that the Chinese space station will...

Im Focus: Alliance „OLED Licht Forum“ – Key partner for OLED lighting solutions

Fraunhofer Institute for Organic Electronics, Electron Beam and Plasma Technology FEP, provider of research and development services for OLED lighting solutions, announces the founding of the “OLED Licht Forum” and presents latest OLED design and lighting solutions during light+building, from March 18th – 23rd, 2018 in Frankfurt a.M./Germany, at booth no. F91 in Hall 4.0.

They are united in their passion for OLED (organic light emitting diodes) lighting with all of its unique facets and application possibilities. Thus experts in...

Im Focus: Mars' oceans formed early, possibly aided by massive volcanic eruptions

Oceans formed before Tharsis and evolved together, shaping climate history of Mars

A new scenario seeking to explain how Mars' putative oceans came and went over the last 4 billion years implies that the oceans formed several hundred million...

Im Focus: Tiny implants for cells are functional in vivo

For the first time, an interdisciplinary team from the University of Basel has succeeded in integrating artificial organelles into the cells of live zebrafish embryos. This innovative approach using artificial organelles as cellular implants offers new potential in treating a range of diseases, as the authors report in an article published in Nature Communications.

In the cells of higher organisms, organelles such as the nucleus or mitochondria perform a range of complex functions necessary for life. In the networks of...

All Focus news of the innovation-report >>>



Industry & Economy
Event News

Virtual reality conference comes to Reutlingen

19.03.2018 | Event News

Ultrafast Wireless and Chip Design at the DATE Conference in Dresden

16.03.2018 | Event News

International Tinnitus Conference of the Tinnitus Research Initiative in Regensburg

13.03.2018 | Event News

Latest News

Modular safety concept increases flexibility in plant conversion

22.03.2018 | Trade Fair News

New interactive map shows climate change everywhere in world

22.03.2018 | Earth Sciences

New technologies and computing power to help strengthen population data

22.03.2018 | Earth Sciences

Science & Research
Overview of more VideoLinks >>>