NSF Award
1353942
An award is being made to the University of Massachusetts Medical School, to develop microsecond mixing devices that will enable researh in biological kinetics. This award made by the Instrument Development for Biological Research, in the Division of Biological Infrastructure (Biological Sciences Directorate) is jointly funded by and the Fluid Dynamics program in the Division of Chemical, Bioengineering, Environmental and Transport Systems (Engineering Directorate). <br/><br/>Non Technical Abstract:<br/>Proteins, RNA and protein-RNA complexes perform many essential functions in cells. Biochemcial reactions occur within a cell on the microsecond to millisecond timescale during which these molecules are present as transiently populated intermediate structures, and are difficult to observe with conventional methods. The folding and assembly of proteins and RNA are examples of biochemical reactions that involve transient intermediates, which scientists investigate in order to better understand how the final functional conformation is generated. Such fundamental studies also help to understand why some minor less populated conformations can result in aberrant function, such as aggregation, as in some human diseases. One approach to studying these partially or transiently populated conformations is to monitor them while the transient conformation is still present at a high population. This requires initiating a reaction very quickly, typically in microseconds, and observing it using a technique that reveals structural information. This project will provide opportunities for graduate students and undergraduates to be traiend in interdisciplinary research that straddles biophysics and fluid dynamics. The investigators hope to partner with companies to commercialize their device, once it is developed and tested. <br/><br/>Technical Abstract:<br/>In this project, the researchers will develop microfluidic devices manufactured from quartz that can initiate folding and assembly reactions by mixing of solutions in microseconds. A unique feature of the device will be its compatibility with small-angle x-ray scattering measurements (SAXS) and other optical probes. SAXS is a spectroscopic tool that reveals information about the size, shape and low-resolution structure of macromolecules. The ultimate goal is to generate structural snapshots of macromolecules at various time points during a reaction (e.g., RNA folding). In these microfluidic devices, once the solutions are mixed, distance becomes linearly proportional to time. By translating the microfluidic device across the beam a series of time measurements is obtained. Previous implementations of microfluidic devices for use with SAXS have been limited by either time resolution or large sample consumption. In this project, the research team will optimize the mixing efficiency using computational fluid dynamics simulations to design a device that can extend from microseconds to hundreds of milliseconds in time range. The device can be easily optimized for use with other probes of secondary, tertiary and quaternary macromolecular structure. This project is an interdisciplinary collaboration between an experimental biophysics group, a computational fluid dynamics group, a national laboratory dedicated to x-ray physics and a microfabrication company specializing in quartz machining. The resulting optimized device will be available to all scientists studying biological macromolecules via SAXS beamlines at national synchrotrons. Workshops involving tutorial and experimental sessions will be provided to new users interested in this technology.
