COLL 48 |
| Daniel K. Schwartz and Grigor Bantchev. Department of Chemical Engineering, University of Colorado, 424 UCB, Boulder, CO 80309 |
| In the presence of a surface or interface proteins generally adsorb and unfold, exposing hydrophobic residues. This is sometimes followed by aggregation and the formation of a gel-like interfacial layer. This process can be favorable (e.g. stabilization of food colloids) or unfavorable (biofouling). Using a combination of interfacial rheology and atomic force microscopy we have studied the connection between the structure of adsorbed b-casein layers (at the air/solution interface) and the mechanical/rheological properties of the interfacial layer. We find that, for sufficiently high protein concentrations, a true interfacial gel forms spontaneously after ~15 hours of aging. This gelation corresponds to the formation of distinctive nanoscale surface aggregates, in particular the coalescence of compact disk-shaped protein aggregates (20-30 nm in diameter) into elongated worm-like aggregates. |
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Nanoscale Imaging of Biological Systems
Division of Colloid and Surface Chemistry |