Forum for Science, Industry and Business

Sponsored by:     3M 
Search our Site:

 

Bacteria spill their guts to aid researchers in quest for new antibiotics

01.07.2004


Protein changes shape to let salts and other solutes in and out of the cell through a process called ’gating’ in order to keep tension on the membrane steady

New findings about a protein that keeps cells alive by opening and closing pores within a cell’s membrane may open the door to the development of new antibiotics. Researchers at UT Southwestern Medical Center at Dallas are studying a protein, called MscL, found in the membrane of the single-cell bacterium Escherichia coli. The protein is essentially an emergency-response valve that changes shape to let salts and other solutes in and out of the cell through a process called "gating" in order to keep tension on the membrane steady. This gating process allows some of the cell’s innards to spill out or liquid from the surrounding environment to rush in.

If this protein – a type of which is found in nearly all microbes – doesn’t function properly, the cell may die. The researchers have refined previous descriptions of MscL, which may have implications for potential drug therapies designed to kill microorganisms. They also developed a novel way to manipulate the protein’s gating, thus killing the bacteria. The findings will appear in an upcoming issue of the Proceedings of the National Academy of Sciences and are available online.



"If you’re looking for targets for drug therapy – and this protein could possibly be one – you need to know what the target looks like and how it functions normally," said Dr. Paul Blount, assistant professor of physiology at UT Southwestern and senior author of the study. "This information may help you predict drug interactions that lead to the desired effect, like killing the organism."

Previous studies on the MscL protein from the bacterium that causes tuberculosis provided the model for what scientists believed was MscL’s structure in its "closed" state. But UT Southwestern researchers led by Dr. Blount found that structure may actually have represented the nearly closed, rather than fully closed, state. Knowing the difference between what the protein’s structure looks like when it is in different conformational states can have important implications if, for example, a scientist is trying to develop a drug that will kill bacteria by interfering with gating.

Dr. Blount and his colleagues developed a new technique to gather information about MscL’s structure and function by monitoring and controlling the channel as it opened and closed. They engineered a mutant E. coli bacterium to contain a substituted amino acid at different sites in the MscL channel protein. When they added a chemical to the environment, the chemical bound to the amino acid, causing, in some instances, the channel protein to change shape, opening the pore inappropriately and killing the cell.

"Not only were we able to examine this protein as it changes shape in a living bacterium, but we also found several sites within the protein that, when modified genetically and chemically, can cause the channel to open inappropriately, thus killing the organism," Dr. Blount said. "If these regions of the protein could be modified pharmacologically, one may have the makings of an antimicrobial agent."

The membrane protein MscL is a mechanosensitive channel protein, a class of proteins that detects mechanical force created by changes in tension in a cell’s membrane. Changes in membrane tension are brought about when the concentration of the fluid surrounding the cell differs from conditions within the cell. In response to changing membrane tension, MscL alters its shape, opening and closing pores in the membrane.

"Mechanosensitive channels such as this change their structure and act as an ’emergency release valve,’ equalizing the conditions on both sides of the cell membrane," Dr. Blount said. "Of course, the ability to detect mechanical forces, whether it is touch, blood pressure or osmotic forces in the kidney, is crucial for essentially all life."

Little is known of how mechanosensors function. Although MscL is the best-studied of these proteins, scientists aren’t in agreement on how the molecule changes its structure as it gates. But, because molecular mechanisms are often conserved, studying the gating mechanism in bacteria may help scientists better understand the process of mechanosensation in humans, Dr. Blount said.

Amanda Siegfried | EurekAlert!
Further information:
http://www.utsouthwestern.edu

More articles from Health and Medicine:

nachricht Skipping Meat on Occasion May Protect Against Type 2 Diabetes
25.06.2019 | Deutsches Institut für Ernährungsforschung Potsdam-Rehbrücke

nachricht Inhaling air pollution-like irritant alters defensive heart-lung reflex for hypertension
19.06.2019 | University of South Florida (USF Innovation)

All articles from Health and Medicine >>>

The most recent press releases about innovation >>>

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

Im Focus: Fraunhofer IDMT demonstrates its method for acoustic quality inspection at »Sensor+Test 2019« in Nürnberg

From June 25th to 27th 2019, the Fraunhofer Institute for Digital Media Technology IDMT in Ilmenau (Germany) will be presenting a new solution for acoustic quality inspection allowing contact-free, non-destructive testing of manufactured parts and components. The method which has reached Technology Readiness Level 6 already, is currently being successfully tested in practical use together with a number of industrial partners.

Reducing machine downtime, manufacturing defects, and excessive scrap

Im Focus: Successfully Tested in Praxis: Bidirectional Sensor Technology Optimizes Laser Material Deposition

The quality of additively manufactured components depends not only on the manufacturing process, but also on the inline process control. The process control ensures a reliable coating process because it detects deviations from the target geometry immediately. At LASER World of PHOTONICS 2019, the Fraunhofer Institute for Laser Technology ILT will be demonstrating how well bi-directional sensor technology can already be used for Laser Material Deposition (LMD) in combination with commercial optics at booth A2.431.

Fraunhofer ILT has been developing optical sensor technology specifically for production measurement technology for around 10 years. In particular, its »bd-1«...

Im Focus: The hidden structure of the periodic system

The well-known representation of chemical elements is just one example of how objects can be arranged and classified

The periodic table of elements that most chemistry books depict is only one special case. This tabular overview of the chemical elements, which goes back to...

Im Focus: MPSD team discovers light-induced ferroelectricity in strontium titanate

Light can be used not only to measure materials’ properties, but also to change them. Especially interesting are those cases in which the function of a material can be modified, such as its ability to conduct electricity or to store information in its magnetic state. A team led by Andrea Cavalleri from the Max Planck Institute for the Structure and Dynamics of Matter in Hamburg used terahertz frequency light pulses to transform a non-ferroelectric material into a ferroelectric one.

Ferroelectricity is a state in which the constituent lattice “looks” in one specific direction, forming a macroscopic electrical polarisation. The ability to...

Im Focus: Determining the Earth’s gravity field more accurately than ever before

Researchers at TU Graz calculate the most accurate gravity field determination of the Earth using 1.16 billion satellite measurements. This yields valuable knowledge for climate research.

The Earth’s gravity fluctuates from place to place. Geodesists use this phenomenon to observe geodynamic and climatological processes. Using...

All Focus news of the innovation-report >>>

Anzeige

Anzeige

VideoLinks
Industry & Economy
Event News

2nd International Conference on UV LED Technologies & Applications – ICULTA 2020 | Call for Abstracts

24.06.2019 | Event News

SEMANTiCS 2019 brings together industry leaders and data scientists in Karlsruhe

29.04.2019 | Event News

Revered mathematicians and computer scientists converge with 200 young researchers in Heidelberg!

17.04.2019 | Event News

 
Latest News

Cooling with the sun

25.06.2019 | Power and Electrical Engineering

Robocabs: The mobility of the future?

25.06.2019 | Studies and Analyses

Skipping Meat on Occasion May Protect Against Type 2 Diabetes

25.06.2019 | Health and Medicine

VideoLinks
Science & Research
Overview of more VideoLinks >>>