Temperature-Dependent Re-alignment of the Short Multifunctional Peptide BP100 in Membranes Revealed by Solid-State NMR Spectroscopy and Molecular Dynamics Simulations.

BP100 is a cationic undecamer peptide with antimicrobial and cell-penetrating activities. The orientation of this amphiphilic α-helix in lipid bilayers was examined under numerous conditions using solid-state F, N and H NMR. At high temperatures in saturated phosphatidylcholine lipids, BP100 lies flat on the membrane surface, as expected.

Overlapping Properties of the Short Membrane-Active Peptide BP100 With (i) Polycationic TAT and (ii) α-helical Magainin Family Peptides.

BP100 is a short, designer-made membrane-active peptide with multiple functionalities: antimicrobial, cell-penetrating, and fusogenic. Consisting of five lysines and 6 hydrophobic residues, BP100 was shown to bind to lipid bilayers as an amphipathic α-helix, but its mechanism of action remains unclear. With these features, BP100 embodies the characteristics of two distinctly different classes of membrane-active peptides, which have been studied in detail and where the mechanism of action is better understood.

Dynamical structure of the short multifunctional peptide BP100 in membranes.

BP100 is a multifunctional membrane-active peptide of only 11 amino acids, with a high antimicrobial activity, an efficient cell-penetrating ability, and low hemolytic side-effects. It forms an amphiphilic α-helix, similar to other antimicrobial peptides like magainin. However, BP100 is very short and thus unlikely to form membrane-spanning pores as proposed for longer peptides as a mechanism of action.

Using the peptide BP100 as a cell-penetrating tool for the chemical engineering of actin filaments within living plant cells.

The delivery of externally applied macromolecules or nanoparticles into living cells still represents a critically limiting step before the full capabilities of chemical engineering can be explored. Molecular transporters such as cell-penetrating peptides, peptoids, and other mimetics can be used to carry cargo across the cellular membrane, but it is still difficult to find suitable sequences that operate efficiently for any particular type of cell. Here we report that BP100 (KKLFKKILKYL-amide), originally designed as an antimicrobial peptide against plant pathogens, can be employed as a fast and efficient cell-penetrating agent to transport fluorescent test cargoes into the cytosol of walled plant cells.