A team of scientists led by Assistant Professor Ganesh S Anand and Professor Linda J. Kenney from the National University of Singapore (NUS) Department of Biological Sciences (DBS) and the Mechanobiology Institute (MBI) has discovered how bacteria respond to salts in their environment and the ways in which salts can alter the behaviour of specialised salt sensor bacterial proteins.
This novel finding sheds light on how microbes detect levels of salts or sugars in their watery environments a problem in biology that has been studied for more than 30 years.
The NUS scientists found that microbes do this by specialised molecules or proteins on the bacterial surface that change shape in response to changes in salt concentration. This is relevant not only to bacteria, but also cells from all organisms which detect and respond to changes in environmental salts and sugars.
The scientists from NUS and the University of Illinois-Chicago (UIC) first published their findings in the EMBO Journal on 30 May 2012.
Salt detecting proteins are like springs
Bacteria have elaborate mechanisms for sensing and responding to changes in the environment. One of the important environmental stresses for bacteria is the changing concentration of salts. For instance, some can live in fresh water (a low salt environment) or in the guts of humans (high salt environment).
Using a powerful combination of a tool called amide hydrogen/deuterium exchange mass spectrometry (HDXMS), accompanied by molecular biology and biochemistry, the scientists from NUS probed how changes in salt concentrations are sensed by a receptor protein.
They found that salt detecting proteins are like molecular springs, or "slinky toys". The proteins are constantly shifting from a condensed spring form to an extended form. Increasing the salt concentration dampens this spring-like movement, which activates the protein. In other words, th
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National University of Singapore