Structure and the movement of ion channels
The PNAS study is important, as biophysics researchers seek to better understand the structure and movement of ion channels because the malfunctioning of these channels is implicated in a number of diseases. For this study, the research team investigated potassium channels built out of four identical subunits, which form a pore through the membrane that can open and close in order to allow or block ion conduction.
They solved a long debate in the field: Do the four subunits of a K+ channel function independently or in a concerted action? To answer this question, the physicists developed a fluorescence spectroscopy technique that allows distinguishing between the subunits so that one can follow, for the first time, the movement of each of the four subunits, information that was lost in previous measurements. They found that the four molecules act together, which explains why no intermediate steps are found in the electrical current measured in electrophysiological experiments.
About the study
"Fluorescence detection of the movement of single KcsA subunits reveals cooperativity," was authored by Blunck R., McGuire H., Hyde H.C., Bezanilla F., and published in the Proceedings of the National Academy of Sciences.