pH-Directed Self-Assembling Helical Peptide Conformation

摘要

The beta-sheet and alpha-helix peptide conformation are two of the most fundamentally ordered secondary structures found in proteins and peptides. They also give rise to self-assembling motifs that form macromolecular channels and nanostructures. Through design these conformations can yield enhanced membrane activity. The self-assembling properties of the beta-sheet and helical peptide motifs have found many applications as antimicrobials and in biomaterials with potential in regenerative medicine. In a delivery or biomaterial system these two conformational motifs can confer nano-strucutral properties that are useful in implantable biomaterials, and non-viral gene formulations. Influenza hemagglutinin (HA) fusion peptides, which were first reported by Wiley et al., possess lytic properties of HA that allow it to gain endosome entry through conformational transition, and is required for membrane fusion activity. The helical peptide's active conformation is formed by way of a pH-triggered change in conformation that is endosomolytic as originally found in HA mutants. Here we discuss helix design properties of some pH-triggered lytic peptides while maintaining a conformation with minimum amino acid chain length requirements.