High concentrated multicomponent protein solutions or “crowded” solutions are prevalent throughout nature and, subsequently, they make a substantial contribution to natural functions. In cells, multicomponent protein concentration can be as high as 50 – 400 mg/ml. This high protein concentration has been found to contribute to a number of natural phenomena. As well, concentrated multicomponent protein solutions are inevitable in a number of bioseparations processes. As examples, concentrated proteins are prevalent in the final preparations of many pharmaceuticals products and, in membrane separations, concentrated proteins are the dominant factor in permeate flux resistance. In fact the very high concentration of proteins at membrane surfaces has been considered one of the most important areas in separations research.
The most dramatic contribution that concentrated proteins exert on their surroundings, whether in living cells or on membrane surfaces, is the highly non-ideal osmotic pressure. Understanding these phenomena can provide a tremendous appreciation of natural functions and provide direct design improvements in new separations methods. The current virial expansion paradigm, based on McMillan-Mayer theory, assumes that the non-idealities observed in the osmotic pressure data from crowded protein solutions are almost exclusively the result of protein-protein interaction.
However, we have developed a novel approach to understanding the osmotic pressure of highly concentrated protein solutions based on a free-solvent model. Uniquely, the associated parameters of the model are both physically realistic and independently measureable. Consequently, the results of this free-solvent model has a wide range of applications from providing insight to observed phenomena to providing the impetus for medical diagnostic tools for detecting protein mutations. This presentation will be discuss the free-solvent model as well as the practical applications of osmotic pressure in bioengineering.
V.G.J. Rodgers is Professor and Chair of Bioengineering at the University of California, Riverside. Dr. Rodgers received his BChE, MSChE and DSc from the University of Dayton, the University of Pittsburgh and Washington University in St. Louis, respectively, all in chemical engineering. Dr. Rodgers is a Fellow of AAAS and AIMBE (American Institute for Medical and Biological Engineering). His research focus is on biotransport phenomena and the osmotic pressure of crowded protein solutions.
When: 10/18/12 4:10 PM
Where: 1005 GBSF