Yuri N. Antonenko, Andreas Horner, Peter Pohl,
"Electrostatically Induced Recruitment of Membrane Peptides into Clusters Requires Ligand Binding at Both Interfaces"
, in PLOS One, Serie 7, Vol. 12, 12-2012
Electrostatically Induced Recruitment of Membrane Peptides into Clusters Requires Ligand Binding at Both Interfaces
Sprache des Titels:
Protein recruitment to specific membrane locations may be governed or facilitated by electrostatic attraction, which originates from a multivalent ligand. Here we explored the energetics of a model system in which this simple electrostatic recruitment mechanism failed. That is, basic poly-L-lysine binding to one leaflet of a planar lipid bilayer did not recruit the triply-charged peptide (O-Pyromellitylgramicidin). Clustering was only observed in cases where PLL was bound to both channel ends. Clustering was indicated (i) by the decreased diffusional PLL mobility DPLL and (ii) by an increased lifetime ?PLL of the clustered channels. In contrast, if PLL was bound to only one leaflet, neither DPLL nor ?P changed. Simple calculations suggest that electrostatic repulsion of the unbound ends prevented neighboring OPg dimers from approaching each other. We believe that a similar mechanism may also operate in cell signaling and that it may e.g. contribute to the controversial results obtained for the ligand driven dimerization of G protein-coupled receptors.