Bilayer disruption and liposome restructuring by a homologous series of small Arg-rich synthetic peptides

Guofeng Ye, Anju Gupta, Robert DeLuca, Keykavous Parang, Geoffrey D. Bothun

Research output: Contribution to journalArticlepeer-review

Abstract

The effects of a series of low molecular weight water-soluble cationic linear peptide analogs (LPAs, n-Arg-Cn-Lys, where Cn represents the saturated alkyl linkage separating the cationic residues (n = 4, 7, or 11) (Ye et al., 2007 [1]). Differential scanning calorimetry results show that the cationic LPAs bound to and disrupted DPPC and, to a greater extent, DPPC/DPPG phase behavior. When added to preformed unilamellar liposomes, the LPAs led to significant structural changes based on cryogenic transmission electron microscopy (cryo-TEM). Coupling cryo-TEM with carboxyfluorescein leakage studies indicate that the LPAs induced permeabilization through bilayer expansion, which caused membrane thinning. The effects were inconsistent with increasing LPA hydrophobicity, which suggests that a cooperative effect between electrostatic binding and hydrophobic insertion determined the location of LPAs within the bilayer and their membrane activity. Our results for LPA-induced membrane disruption correlate with previous breast cancer cell uptake studies that showed minimal LPA-C4 uptake, but high LPA-C11 uptake through a non-endocytic mechanism.

Original languageEnglish (US)
Pages (from-to)76-81
Number of pages6
JournalColloids and Surfaces B: Biointerfaces
Volume76
Issue number1
DOIs
StatePublished - Mar 1 2010
Externally publishedYes

Keywords

  • Domain
  • Lipid bilayer
  • Liposome
  • Peptide
  • Permeability
  • Phase behavior

ASJC Scopus subject areas

  • Biotechnology
  • Colloid and Surface Chemistry
  • Physical and Theoretical Chemistry
  • Surfaces and Interfaces

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