Biophysics Cell Membrane Probe

Brownell, William

Abstract

A Biophysics Cell Membrane Probe (BCMProbe) is requested to expand biophysical studies on the membranes of living cells. The BCMProbe consists of optical tweezers integrated with an electrophysiology patch-clamp module and a standing wave microscope. The BCMProbe is a novel, unique instrument that can be used to modulate membrane mechanics as well as the magnitude of the electric field across it. At the same time it can measure the force produced by the membrane and the membrane current. Major users will exploit the instrument to further examine membrane electromechanics and actin bundling in nanoscale membrane tubes, measure charge movement associated with cell deformation and examine the self association as well as the mobility of integral membrane proteins. We will be able to expand our previous work that has demonstrated cell membranes capable of converting electrical energy directly into mechanical energy at acoustic frequencies. In addition we will to increase our understanding of mechanotransduction in Merkel cells, an epidermal mechano-sensory cell. The BCMProbe will be a new instrument at Baylor College of Medicine and its design is based on over 10 years of experience gained in constructing a previous model. The new instrument will be enhanced by super-resolution microscopy, electro-optic deflectors and complete system integration. The design is modular so that a variety of user specific experiments such as calcium imaging, fluorescence recovery after photobleaching or fluorescence resonance energy transfer may be easily accommodated. Our users have extensive expertise in optical approaches to membrane biophysics and mechanotransduction in sensory systems. The work will have implications beyond the hearing and somatosensory systems as it will reveal fundamental membrane mechanisms. These mechanisms have implications for understanding membrane transport and even learning and memory. While the obvious beneficiaries of the instrument will be the hard of hearing and individuals with touch disorders, solutions for other clinical problems will undoubtedly arise because every cell and the organelles within are enclosed by a membrane.