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 of a 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 (?Goads) 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 T are glycine and threonine amino acid residues and X represents a variable residue. In this paper, we report ?Goads 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 ?Goads 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.