The environment of a cell is highly crowded with proteins and nucleic acids. Unfortunately, the study of biochemical reaction kinetics in vitro has been limited to very dilute conditions. Microfluidics may provide a platform to investigate biochemical reactions in crowded conditions like those of the cell. The laboratories of Jamie Cate and Arun Majumdar will optimize a Microfluidics mixer with the goal to achieve millisecond time resolution in high concentrations of a crowding agent such as Bovine Serum Albumin (BSA). Once developed, such a mixing platform will be of general use to biochemists studying a wide range of biochemical phenomena, under conditions more closely matching those in the cell. During the first year of funding, the laboratories will characterize numerous mixer geometries to better understand mixing timescales and characteristics. Association of the small and large ribosomal subunits from Escherichia coli will be used as a test case for the effectiveness of the Microfluidics platform. The rate and degree of ribosomal subunit association will be measured under different levels of molecular crowding. Furthermore, the ionic conditions will be varied to reflect either in vitro biochemical conditions, or conditions that more closely match those thought to exist in E. coli. Graduate students and postdoctoral associates will receive interdisciplinary training in mechanical engineering and biochemistry.
