Levich Institute Seminar Announcement, 11/13/2007
Tuesday, 11/13/2007
4:00 PM
Mudd Building, Room #825
500 West 120th Street
Columbia University

Professor Abraham Lenhoff
University of Delaware
Department of Chemical Engineering

"Crystallization and Other Adventures on the Protein Phase Diagram "


[This is a CCNY/Columbia NSF-IGERT Soft Materials seminar]

ABSTRACT


The phase behavior of protein solutions is exploited in numerous applications, such as precipitation and crystallization in protein separations, crystallization in structural biology and gelation in food processing. However, the relation of these operations to the phase diagram is not always clearly defined, and detailed phase diagrams have been measured for only two proteins, so the phase diagram per se has found only limited use in seeking optimal process conditions. Probably the closest explicit link between a direct property measurement and selection of process conditions for proteins is a correlation, developed by George and Wilson, of the osmotic second virial coefficient with solution conditions conducive to crystallization. This presentation will discuss efforts to build on the empirical correlation, including more efficient measurement of protein interactions by self-interaction chromatography, making possible a much more extensive exploration of protein interaction trends as a function of solution conditions than has previously been possible. In addition, the mechanistic basis for the observed correlation is explored within the context of the protein phase diagram, such as the role of a metastable liquid-liquid phase envelope. The possible relation to other phenomena encountered in separation processes, such as aggregation, will also be discussed.

BRIEF ACADEMIC/EMPLOYMENT BACKGROUND:

  • 2005- Director, NIH Center of Biomedical Research Excellence on Membrane Protein Production and Characterization, University of Delaware
  • 2002- Gore Professor of Chemical Engineering, University of Delaware, Newark, DE
  • 2000-2005 Director, NIH Center of Biomedical Research Excellence in Structural and Functional Genomics, University of Delaware
  • 1996- Professor, Department of Chemical Engineering, University of Delaware, Newark, DE
  • 1990-1996 Associate Professor, Department of Chemical Engineering, University of Delaware, Newark, DE
  • Ph.D. in Chemical Engineering, University of Wisconsin-Madison, 1984. Thesis (under Prof. E. N. Lightfoot): Convective Dispersion and Interphase Mass Transfer.