Incorporation and characterization of alpha-helical peptide-based anchors into bead-supported lipid bilayer membranes

Our aim is to design alpha-helical peptide complexes to enhance their stability and biological feasibility for the study of membrane proteins and their interactions. In on-going work, we employ (K₃A₄L₂A₇L₂A₃K₃) as anchoring molecules, where conjugation of the peptide with fluoresceine isothiocyanate (FITC) allows one to access a variety of chemistries (such as introducing fluorescent dye, etc.) for orthogonal modification. These peptides partition within NHS-PEG3000-NHS which function as in vitro models for interactions with the membrane, will be incorporated into mimic lipid bilayer membranes (such as DOPC) supported by microbeads. We could control the receptor site densities on lipobeads by varying the mole fraction of different lipids and ligands. 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. Variations in the peptide sequence allow us to rationally investigate the influence of sequence on peptide anchor stability.