Branched amphipathic oligo-peptides that self-assemble into vesicles

Abstract

The present invention provides branched amphipathic peptides and vesicles formed thereof. The peptides comprise a polar/positively charged C-terminal segment, a branch point, and two hydrophobic N-terminal segments extending from the branch point. The vesicles are formed using a plurality of first and second peptides, wherein the first peptide has a different chain length from the second peptide. When a plurality of the first and second peptides are mixed together, they self-assemble to form small spheres defined by a membrane consisting of an interlocking peptide network bilayer and having a liquid-receiving interior space (i.e., hollow core). In the bi-layer, the respective hydrophobic segments of the peptides form beta-sheet structures having a hydrogen bond-stabilized, anti-parallel orientation in which the opposed sequences interlock to form a zipper-like structure in three dimensions. Thus, the peptide assembly (i.e., vesicle) can be held together at reduced concentrations where lipid vesicles would breakdown.