Human hearing, along with our ability to maintain balance and regulate our cardiovascular systems, depends on “mechanoreceptors” that respond to pressure and other stimuli.  Still, scientists know much less about how they work than they do about the mechanisms involved in other senses such as taste, sight, and touch.

Dr. Sergei Sukharev, Associate Professor of Biology in the College of Chemical and Life Sciences, is investigating the cell receptors that are involved in regulating our cardiovascular systems. This work builds upon his recent breakthrough in understanding how mechanoreceptors function in E. coli bacteria. Scientists believe that the basic mechanisms of bacterial mechanoreceptors are similar to the force receptors in mammals and can use this new knowledge to better understand complex human physiology.

A Leader in Biophysics Research

The Biophysical Society honored Sukharev with the 2008 Michael & Kate Barany Award for Young Investigators in February for his important contribution to biophysics. Dr. Sukharev solved the puzzle of how bacterial mechanoreceptors work by opening pathways in their usually tightly sealed membrane in response to tension. This process is what enables bacteria and bugs to adjust their internal pressure.

Sensing Stress: Bacterial and Mammalian Cells Do It

 “When it rains, bugs tend to swell,” Sukharev explains. “In order to avoid rupture, they open little holes and spit out substances that are not needed. This way, they can reduce their solute content inside and reduce the osmotic pressure. Their survival depends on the function of these channels.”

Dr. Sukharev’s research powerfully combines biophysical experiments with new techniques in molecular computation. To envision how the cell channel opens and establish the precise roles of the membrane proteins, Sukharev first predicted how the gate would open and close using computer simulations.  He then mutated specific amino acids in the receptor and observed how these changes affected the gating mechanism for ion flow. He measured the changes in ion flow using electrophysiological techniques, and modeled the effect of the mutation on the three-dimensional structure of the protein through large-scale molecular dynamics simulations. (see 3-D animation)

"Elegant" Experiments Lauded as Biophysics Tour de Force

Sukharev’s accomplishments in this challenging area of molecular biophysics have been widely lauded.  “Professor Sukharev’s elegant work on bacterial mechanoreceptors is a ‘tour de force’ that establishes him as a leader in the international molecular biophysics community,” says Norma Allewell, Dean of the College of Chemical and Life Sciences.