title: Effects of topology, length, and charge on the activity of a kininogen-derived peptide on lipid membranes and bacteria.
abstract: Effects of topology, length, and charge on peptide interactions with lipid bilayers was investigated for variants of the human kininogen-derived peptide HKH20 (HKHGHGHGKHKNKGKKNGKH) by ellipsometry, CD, fluorescence spectroscopy, and z-potential measurements. The peptides display primarily random coil conformation in buffer and at lipid bilayers, and their lipid interaction is dominated by electrostatics, the latter evidenced by higher peptide adsorption and resulting membrane rupture for an anionic than for a zwitterionic membrane, as well as by strongly reduced adsorption and membrane rupture at high ionic strength. At sufficiently high peptide charge density, however, electrostatic interactions contribute to reducing the peptide adsorption and membrane defect formation. Truncating HKH20 into overlapping 10 amino acid peptides resulted in essentially eliminated membrane rupture and in a reduced amount peptide charges pinned at the lipid bilayer. Finally, cyclic HKH20 was found to be less efficient than the linear peptide in causing liposome rupture, partly due to a lower adsorption. Analogous results were found regarding bactericidal effects.
authors.affiliation: Department of Pharmacy, Uppsala University, P.O. Box 580, SE-751 23 Uppsala, Sweden.
authors.forename: Lovisa
authors.initials: L
authors.lastname: Ringstad
authors.forename: Lukasz
authors.initials: L
authors.lastname: Kacprzyk
authors.forename: Artur
authors.initials: A
authors.lastname: Schmidtchen
authors.forename: Martin
authors.initials: M
authors.lastname: Malmsten
mesh_terms: D000327:Adsorption; D000595:Amino Acid Sequence; D002942:Circular Dichroism; D004926:Escherichia coli / Q000187:drug effects / Q000302:isolation & purification; D006801:Humans; D007526:Isoelectric Point; D007704:Kininogens / Q000737:chemistry*; D008051:Lipid Bilayers / Q000737:chemistry / Q000378:metabolism*; D008563:Membrane Lipids / Q000737:chemistry / Q000378:metabolism*; D008969:Molecular Sequence Data; D009842:Oligopeptides / Q000737:chemistry / Q000378:metabolism / Q000494:pharmacology; D009994:Osmolar Concentration; D010455:Peptides / Q000138:chemical synthesis / Q000737:chemistry* / Q000378:metabolism* / Q000494:pharmacology; D011487:Protein Conformation; D017433:Protein Structure, Secondary; D011550:Pseudomonas aeruginosa / Q000187:drug effects / Q000302:isolation & purification; D013050:Spectrometry, Fluorescence; D013211:Staphylococcus aureus / Q000187:drug effects / Q000302:isolation & purification; D055672:Static Electricity
chemical_list: D007704:Kininogens; D008051:Lipid Bilayers; D008563:Membrane Lipids; D009842:Oligopeptides; D010455:Peptides