| AVS 56th International Symposium & Exhibition | |
| Biomaterial Interfaces | Tuesday Sessions |
| Session BI-TuM |
| Session: | Proteins and Cell Interactions at Interfaces II |
| Presenter: | K. Fears, US Naval Research Laboratory |
| Authors: | K. Fears, US Naval Research Laboratory J. Kulp III, US Naval Research Laboratory D.Y. Petrovykh, US Naval Research Laboratory T. Clark, US Naval Research Laboratory |
| Correspondent: | Click to Email |
The stable structure of beta-helical peptides in solution provides a well-defined starting point for discerning the changes in secondary structure of peptides induced by surface adsorption. Understanding the adsorption of proteins on surfaces is of critical importance in medical- and bio-technology. The determination of the secondary and higher-order structure of adsorbed proteins, however, is challenging due to their inherent complexity. Peptides with simple secondary structures provide a good model for investigating the interactions between surfaces and the structural subunits of proteins. Beta-helical, rather than alpha-helical, peptides were selected for this study because of their stability and tendency to maintain a monomeric, unaggregated structure. Peptides were custom designed to switch between two different stable conformations as a function of solvent composition, as confirmed by nuclear magnetic resonance (NMR) and circular dichroism (CD) spectroscopies in solution. These peptides were adsorbed onto silica substrates from aqueous and organic solvents to determine their conformation post-adsorption. The secondary structure assignments of the adsorbed peptides were based on the comparison of their CD spectra to spectra of the same peptides in their known solution conformation. Our ability to measure the secondary structure of peptides that are adsorbed as monolayers on planar substrates suggests that CD spectroscopy can be used to gain insight about the adsorption behavior of individual subunits that provide support and/or functionality to proteins.