title: Single-molecule electrophoresis of beta-hairpin peptides by electrical recordings and Langevin dynamics simulations.
abstract: We used single-channel electrical recordings and Langevin molecular dynamics simulations to explore the electrophoretic translocation of various beta-hairpin peptides across the staphylococcal alpha-hemolysin (alphaHL) protein pore at single-molecule resolution. The beta-hairpin peptides, which varied in their folding properties, corresponded to the C terminal residues of the B1 domain of protein G. The translocation time was strongly dependent on the electric force and was correlated with the folding features of the beta-hairpin peptides. Highly unfolded peptides entered the pore in an extended conformation, resulting in fast single-file translocation events. In contrast, the translocation of the folded beta-hairpin peptides occurred more slowly. In this case, the beta-hairpin peptides traversed the alphaHL pore in a misfolded or fully folded conformation. This study demonstrates that the interaction between a polypeptide and a beta-barrel protein pore is dependent on the folding features of the polypeptide.
authors: Carl P
authors: CP
authors: Goodrich
authors: Serdal
authors: S
authors: Kirmizialtin
authors: Beatrice M
authors: BM
authors: Huyghues-Despointes
authors: Aiping
authors: A
authors: Zhu
authors: J Martin
authors: JM
authors: Scholtz
authors: Dmitrii E
authors: DE
authors: Makarov
authors: Liviu
authors: L
authors: Movileanu
mesh_terms: D000107:Acetylation; D000595:Amino Acid Sequence; D019943:Amino Acid Substitution; D001426:Bacterial Proteins / Q000737:chemistry*; D001427:Bacterial Toxins / Q000737:chemistry*; D003198:Computer Simulation; D004586:Electrophoresis / Q000379:methods; D006460:Hemolysin Proteins / Q000737:chemistry*; D008051:Lipid Bilayers; D008564:Membrane Potentials; D008969:Molecular Sequence Data; D010455:Peptides / Q000737:chemistry*; D017510:Protein Folding; D017433:Protein Structure, Secondary; D021381:Protein Transport
chemical_list: D001426:Bacterial Proteins; D001427:Bacterial Toxins; D006460:Hemolysin Proteins; C034284:IgG Fc-binding protein, Streptococcus; D008051:Lipid Bilayers; D010455:Peptides; C021091:staphylococcal alpha-toxin