title: Unimolecular study of the interaction between the outer membrane protein OmpF from E. coli and an analogue of the HP(2-20) antimicrobial peptide.
abstract: Little is known on antimicrobial peptide permeation through outer membrane channels in gram-negative bacteria. Herein, we probed at a single-molecule level the interaction of two different peptides, magainin 2 and HPA3P with OmpF from E. coli. HPA3P is an analogue of the antimicrobial peptide HP(2-20) isolated from the N-terminal region of the Helicobacter pylori ribosomal protein. Our data show that the shorter and more charged HPA3P peptide is more accessible to the inner volume of the OmpF than magainin 2. We demonstrate the ability of HPA3P peptides to interact with OmpF in a voltage- and concentration-dependent manner, which does not rule out a novel mechanism by which such peptides could reach the periplasmic space of gram-negative bacteria. Unexpectedly, we found that increasing the applied voltage led to an increase of the residence time of HPA3P peptide inside the pore, possibly reflecting electric field-induced changes in pore and peptide geometry.
authors.affiliation: Faculty of Physics, Laboratory of Biophysics and Medical Physics, Alexandru I. Cuza' University, Blvd. Carol I, No. 11, Iasi, 700506, Romania.
authors.forename: Aurelia
authors.initials: A
authors.lastname: Apetrei
authors.forename: Alina
authors.initials: A
authors.lastname: Asandei
authors.forename: Yoonkyung
authors.initials: Y
authors.lastname: Park
authors.forename: Kyung-Soo
authors.initials: KS
authors.lastname: Hahm
authors.forename: Mathias
authors.initials: M
authors.lastname: Winterhalter
authors.forename: Tudor
authors.initials: T
authors.lastname: Luchian
mesh_terms: D000595:Amino Acid Sequence; D001425:Bacterial Outer Membrane Proteins / Q000235:genetics / Q000378:metabolism*; D004594:Electrophysiology; D004926:Escherichia coli; D029968:Escherichia coli Proteins / Q000378:metabolism*; D008958:Models, Molecular; D008969:Molecular Sequence Data; D010446:Peptide Fragments / Q000235:genetics / Q000378:metabolism*; D018272:Porins / Q000737:chemistry / Q000378:metabolism*; D012269:Ribosomal Proteins / Q000235:genetics / Q000378:metabolism*
chemical_list: D001425:Bacterial Outer Membrane Proteins; D029968:Escherichia coli Proteins; C530859:HPA3 peptide; C109237:OmpF protein; D010446:Peptide Fragments; D018272:Porins; D012269:Ribosomal Proteins