(722ba) Synthesis and Characterization of Alpha-Helical Peptide-Based Anchors for Tether Supported Membranes

We have applied rationally designed peptide anchors to a lipid bilayer interface in order to enhance the viability of a supported lipid membrane anchored to a substrate via polymer tethers. Our aim is to design these supramolecular complexes to enhance their stability and biological feasibility for the study of membrane proteins and their interactions. In current work, we employ alpha-helical peptides (K3A4L2A7L2A3K3) as anchoring molecules, where conjugation of the peptide with N-hydroxysuccinimide (NHS)-esters through amine-based coupling allows one to access a variety of chemistries for orthogonal modification.

These peptides partition within surfactant micelles, which function as in vitro models for interactions with the membrane. Moreover, the secondary structure of peptide within these micelles is characterized with circular dichroism. Lateral fluidity of the fluorescently tagged peptide is analyzed via fluorescence imaging microscopy (Confocal Microscopy) and quantified using fluorescence recovery after photobleaching (FRAP) techniques. Lastly, we inspect the peptide-based anchor in detail via Nuclear Magnetic Resonance (NMR), which will supply data to evaluate the structural properties of the anchor within the bilayer. Variations in the peptide sequence allow us to rationally investigate the influence of sequence on peptide anchor stability.