COLL 422 |
| Daniel K. Schwartz1, Grigor Bantchev1, Christine R. Vessely2, Amber Clausi1, and John F. Carpenter2. (1) Department of Chemical Engineering, University of Colorado, 424 UCB, Boulder, CO 80309, (2) Department of Pharmaceutical Sciences, University of Colorado Health Sciences Center, 4200 East 9th Avenue, Denver, CO 80262 |
| In the presence of a surface or interface proteins generally adsorb and denature, exposing hydrophobic residues. This may be followed by interfacial aggregation and the formation of a gel-like interfacial layer. This process can be favorable (e.g. stabilization of food colloids) or unfavorable (e.g. biofouling, destabilization of therapeutic proteins). We have studied this process at the air/solution interface using a combination of interfacial rheology, infrared spectroscopy, and atomic force microscopy. Two examples will be described: (1) beta-casein, a disordered milk protein incapable of forming covalent cross-links, was nevertheless observed to form an interfacial gel forms after ~15 hours of aging. The gelation process appears to be connected to the formation of distinctive nanoscale surface aggregates, in particular the coalescence of compact disk-shaped protein nanoparticles (20-30 nm in diameter) into elongated worm-like aggregates. (2) A model monoclonal antibody in which the kinetics of interfacial gelation depend sensitively on solution conditions. Connections between the interfacial behavior and the phenomenon of “agitation-induced aggregation” will be discussed. |
|
Surface and Colloid Chemistry Award Symposium Honoring Joseph Zasadzinski
2:00 PM-5:00 PM, Wednesday, March 31, 2004 Marriott -- Orange County 3, Oral
Division of Colloid and Surface Chemistry |