Forum for Science, Industry and Business

Sponsored by:     3M 
Search our Site:

 

Researchers Find Color Sensitive Atomic Switch in Bacteria

05.11.2004


Researchers using extremely high resolution imaging have found an atomic switch capable of discriminating color in a bacterial membrane protein.



In a paper posted today on Science Express, the rapid advance publication page of Science, scientists from The University of Texas Medical School at Houston and the University of California , Irvine , describe the versatile light-sensing protein at levels of resolution smaller than a nanometer – one billionth of a meter.

“High-resolution X-ray crystallography revealed the light-absorbing part of the protein was present in two alternative positions, suggesting to us that light of different colors drives this protein back and forth between two differently colored states of the protein,” said corresponding author John L. Spudich, Ph.D., director of the Center for Membrane Biology in the UT Medical School Department of Biochemistry and Molecular Biology. “Chemical analysis and spectroscopic methods then proved that the switch, buried in the middle of this membrane-embedded protein, similar in structure to our visual pigments, is controlled by blue versus orange photon absorption.” Spudich said.


That function makes the protein novel among its family of light-sensing proteins known as rhodopsins, which are present in microbes and higher animals. In human eyes, rhodopsin is the light-absorbing pigment of the rods, located in the retina. The team studied a new-found rhodopsin on the surface membrane of the bacterium Anabaena, classified as “blue-green algae” or cyanobacteria, which rely on photosynthesis to generate energy.

Having a single sensory protein capable of distinguishing color would provide Anabaena with information about the color of light available in its environment, enabling more efficient harvesting of light for photosynthesis, Spudich said. “Understanding rhodopsins helps us understand the large number of related membrane receptors involved in cell signaling that govern biological functions,” Spudich said. In the longer term, the novel protein found in Anabaena has the potential to be used in nano-machinery as a color-sensor; however the authors point out that this practical application is years in the future.

First author of the paper is Lutz Vogeley, a graduate student in the UC Irvine Department of Molecular Biology and Biochemistry. Senior authors are Dr. Spudich and Dr. Hartmut Luecke, Ph.D., professor of molecular biology and biochemistry and of physiology and biophysics at UC-Irvine. Co-authors include Oleg Sineshchekov, Ph.D., of Moscow State University in Russia, and visiting professor in the UT Center for Biology, and research fellow Vishwa Trivedi, Ph.D., and Jun Sasaki, Ph.D., assistant professor, both of the UT Center for Membrane Biology. “One of the key frontiers of biomedical science in the genomic era is the crucial role of cell membranes in normal cell function and disease states,” said Spudich, who holds the Robert A. Welch Distinguished Chair in Chemistry and is a professor in the UT Graduate School of Biomedical Sciences. “Ask virtually any investigator and you’ll find his or her research program bumps up against a membrane.”

Cell membrane surfaces and their exposed proteins are the most accessible targets to treat human tissue or destroy infectious microbes, he said. More than 60 percent of medications target membrane proteins on human cells and many antibiotics target membranes on pathogens.

Scott Merville | EurekAlert!
Further information:
http://www.uth.tmc.edu

More articles from Life Sciences:

nachricht Water forms 'spine of hydration' around DNA, group finds
26.05.2017 | Cornell University

nachricht How herpesviruses win the footrace against the immune system
26.05.2017 | Helmholtz-Zentrum für Infektionsforschung

All articles from Life Sciences >>>

The most recent press releases about innovation >>>

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

Im Focus: Can the immune system be boosted against Staphylococcus aureus by delivery of messenger RNA?

Staphylococcus aureus is a feared pathogen (MRSA, multi-resistant S. aureus) due to frequent resistances against many antibiotics, especially in hospital infections. Researchers at the Paul-Ehrlich-Institut have identified immunological processes that prevent a successful immune response directed against the pathogenic agent. The delivery of bacterial proteins with RNA adjuvant or messenger RNA (mRNA) into immune cells allows the re-direction of the immune response towards an active defense against S. aureus. This could be of significant importance for the development of an effective vaccine. PLOS Pathogens has published these research results online on 25 May 2017.

Staphylococcus aureus (S. aureus) is a bacterium that colonizes by far more than half of the skin and the mucosa of adults, usually without causing infections....

Im Focus: A quantum walk of photons

Physicists from the University of Würzburg are capable of generating identical looking single light particles at the push of a button. Two new studies now demonstrate the potential this method holds.

The quantum computer has fuelled the imagination of scientists for decades: It is based on fundamentally different phenomena than a conventional computer....

Im Focus: Turmoil in sluggish electrons’ existence

An international team of physicists has monitored the scattering behaviour of electrons in a non-conducting material in real-time. Their insights could be beneficial for radiotherapy.

We can refer to electrons in non-conducting materials as ‘sluggish’. Typically, they remain fixed in a location, deep inside an atomic composite. It is hence...

Im Focus: Wafer-thin Magnetic Materials Developed for Future Quantum Technologies

Two-dimensional magnetic structures are regarded as a promising material for new types of data storage, since the magnetic properties of individual molecular building blocks can be investigated and modified. For the first time, researchers have now produced a wafer-thin ferrimagnet, in which molecules with different magnetic centers arrange themselves on a gold surface to form a checkerboard pattern. Scientists at the Swiss Nanoscience Institute at the University of Basel and the Paul Scherrer Institute published their findings in the journal Nature Communications.

Ferrimagnets are composed of two centers which are magnetized at different strengths and point in opposing directions. Two-dimensional, quasi-flat ferrimagnets...

Im Focus: World's thinnest hologram paves path to new 3-D world

Nano-hologram paves way for integration of 3-D holography into everyday electronics

An Australian-Chinese research team has created the world's thinnest hologram, paving the way towards the integration of 3D holography into everyday...

All Focus news of the innovation-report >>>

Anzeige

Anzeige

Event News

Marine Conservation: IASS Contributes to UN Ocean Conference in New York on 5-9 June

24.05.2017 | Event News

AWK Aachen Machine Tool Colloquium 2017: Internet of Production for Agile Enterprises

23.05.2017 | Event News

Dortmund MST Conference presents Individualized Healthcare Solutions with micro and nanotechnology

22.05.2017 | Event News

 
Latest News

How herpesviruses win the footrace against the immune system

26.05.2017 | Life Sciences

Water forms 'spine of hydration' around DNA, group finds

26.05.2017 | Life Sciences

First Juno science results supported by University of Leicester's Jupiter 'forecast'

26.05.2017 | Physics and Astronomy

VideoLinks
B2B-VideoLinks
More VideoLinks >>>