Langmuir, Vol.25, No.10, 5637-5646, 2009
Benchmark Experimental Data Set and Assessment of Adsorption Free Energy for Peptide-Surface Interactions
With the increasing interest in protein adsorption in fields ranging from bionanotechnology to biomedical engineering, there is a growing need to understand protein-surface interactions at a fundamental level, Such as the interaction between individual amino acid residues ON protein and functional groups presented by a surface. However, relatively little data are available that experimentally provide a quantitative, comparative measure of these types of interactions. To address this deficiency, the objective Of this Study was to generate a database of experimentally measured standard state adsorption free energy (Delta G(ads)(o)) values for a wide variety of amino acid residue-surface interactions using a host-guest peptide and alkanethiol self-assembled monolayers (SAMs) with polymer-like functionality as the model system. The host-guest amino acid sequence was synthesized in the form of TGTG-X-GTGT, where G and Tare glycine and threonine amino acid residues and X represents a variable residue. In this paper, we report Delta G(ads)(o) values for the adsorption of 12 different types of the host-guest peptides on a set of nine different SAM surfaces, for a total of 108 peptide-surface systems. The Delta G(ads)(o) values for these 108 peptide-surface combinations show clear trends in adsorption behavior that are dependent on both peptide composition and surface chemistry. These data provide a benchmark experimental data set from which fundamental interactions that govern peptide and protein adsorption behavior can be better understood and compared.