Thermodynamic Characterization of Self-Assembled Peptides on Graphite

Abstract

Protein adsorption on solid surfaces has been gaining wide interests in the fields of drag delivery, biosensor, and biomedical diagnosis. Peptides, small proteins, also bind to solid surfaces. Recently, there are a variety of peptides have been developed and reported which show not only a binding affinity on solid surfaces but also spontaneous organizing into long-range ordered structures on surfaces. We investigate the thermal stability of self-assembled peptides on graphite. We utilized graphite binding peptide 5 (GrBP5), which is selected by phage display method. Using atomic force microscopy, we characterized the morphology of peptide nanostructures at various temperatures. GrBP5 assembled into two phases with six-fold symmetry, resulting in phase transition over time. Upon the temperature control, kinetics of the phase transition was studied to evaluate the thermodynamic stability of each phase of the self-assembled peptides.