title: Impact of peptide clustering on unbinding forces in the context of fusion mimetics.
abstract: Coiled-coil zipping and unzipping is a pivotal process in SNARE-regulated membrane fusion. In this study we examine this process mediated by a minimal model for coiled-coil formation employing force spectroscopy in the context of membrane-coated surfaces and probes. The interaction forces of several hundred pN are surprisingly low considering the proposed amount of molecular bonds in the contact zone. However, by means of high-resolution imaging employing atomic force microscopy and studying the lateral mobility of lipids and peptides as a function of coiled-coil formation, we are able to supply a detailed view on processes occurring on the membrane surfaces during force measurements. The interaction forces determined here are not only dependent on the peptide concentration on the surface, but also on the regional organization of lateral peptide clusters found prior to coiled-coil formation.
authors.affiliation: Institute of Physical Chemistry, Tammannstr. 6, University of Goettingen, 37077 Göttingen, Germany.
authors.forename: Gesa
authors.initials: G
authors.lastname: Pähler
authors.forename: Bärbel
authors.initials: B
authors.lastname: Lorenz
authors.forename: Andreas
authors.initials: A
authors.lastname: Janshoff
mesh_terms: D040761:Biomimetic Materials / Q000138:chemical synthesis / Q000737:chemistry*; D055666:Lipopeptides / Q000138:chemical synthesis / Q000737:chemistry*; D008561:Membrane Fusion; D018625:Microscopy, Atomic Force; D011485:Protein Binding; D055503:Protein Multimerization; D017434:Protein Structure, Tertiary; D050600:SNARE Proteins / Q000737:chemistry*
chemical_list: D055666:Lipopeptides; D050600:SNARE Proteins