Modulation of the Spontaneous Curvature and Bending Rigidity of Lipid Membranes by Interfacially Adsorbed Amphipathic Peptides Export

@article{Zemel_2008_JPCB, abstract = {PMID: 18479112 Amphipathic α-helical peptides are often ascribed an ability to induce curvature stress in lipid membranes. This may lead directly to a bending deformation of the host membrane, or it may promote the formation of defects that involve highly curved lipid layers present in membrane pores, fusion intermediates, and solubilized peptide−micelle complexes. The driving force is the same in all cases: peptides induce a spontaneous curvature in the host lipid layer, the sign of which depends sensitively on the peptide's structural properties. We provide a quantitative account for this observation on the basis of a molecular-level method. To this end, we consider a lipid membrane with peptides interfacially adsorbed onto one leaflet at high peptide-to-lipid ratio. The peptides are modeled generically as rigid cylinders that interact with the host membrane through a perturbation of the conformational properties of the lipid chains. Through the use of a molecular-level chain packing theory, we calculate the elastic properties, that is, the spontaneous curvature and bending stiffness, of the peptide-decorated lipid membrane as a function of the peptide's insertion depth. We find a positive spontaneous curvature (preferred bending of the membrane away from the peptide) for small penetration depths of the peptide. At a penetration depth roughly equal to half-insertion into the hydrocarbon core, the spontaneous curvature changes sign, implying negative spontaneous curvature (preferred bending of the membrane toward the peptide) for large penetration depths. Despite thinning of the membrane upon peptide insertion, we find an increase in the bending stiffness. We discuss these findings in terms of how the peptide induces elastic stress.}, address = {Department of Physical Chemistry and the Fritz Haber Research Center, The Hebrew University, Jerusalem 91904, Israel, Department of Physics, North Dakota State University, Fargo, North Dakota 58105-5566}, author = {Zemel, Assaf and Ben-Shaul, Avinoam and May, Sylvio}, citeulike-article-id = {2814538}, citeulike-linkout-0 = {http://dx.doi.org/10.1021/jp711107y}, citeulike-linkout-1 = {http://pubs.acs.org/doi/abs/10.1021/jp711107y}, day = {1}, doi = {10.1021/jp711107y}, journal = {The Journal of Physical Chemistry B}, keywords = {2009\_nserc\_usra, lipid\_membrane, phys\_chem}, month = {June}, number = {23}, pages = {6988--6996}, posted-at = {2009-08-07 00:20:59}, priority = {2}, title = {Modulation of the Spontaneous Curvature and Bending Rigidity of Lipid Membranes by Interfacially Adsorbed Amphipathic Peptides}, url = {http://dx.doi.org/10.1021/jp711107y}, volume = {112}, year = {2008} }

TY - JOUR ID - Zemel_2008_JPCB L3 - citeulike-article-id:2814538 N2 - PMID: 18479112 Amphipathic α-helical peptides are often ascribed an ability to induce curvature stress in lipid membranes. This may lead directly to a bending deformation of the host membrane, or it may promote the formation of defects that involve highly curved lipid layers present in membrane pores, fusion intermediates, and solubilized peptide−micelle complexes. The driving force is the same in all cases: peptides induce a spontaneous curvature in the host lipid layer, the sign of which depends sensitively on the peptide’s structural properties. We provide a quantitative account for this observation on the basis of a molecular-level method. To this end, we consider a lipid membrane with peptides interfacially adsorbed onto one leaflet at high peptide-to-lipid ratio. The peptides are modeled generically as rigid cylinders that interact with the host membrane through a perturbation of the conformational properties of the lipid chains. Through the use of a molecular-level chain packing theory, we calculate the elastic properties, that is, the spontaneous curvature and bending stiffness, of the peptide-decorated lipid membrane as a function of the peptide’s insertion depth. We find a positive spontaneous curvature (preferred bending of the membrane away from the peptide) for small penetration depths of the peptide. At a penetration depth roughly equal to half-insertion into the hydrocarbon core, the spontaneous curvature changes sign, implying negative spontaneous curvature (preferred bending of the membrane toward the peptide) for large penetration depths. Despite thinning of the membrane upon peptide insertion, we find an increase in the bending stiffness. We discuss these findings in terms of how the peptide induces elastic stress. IS - 23 JF - The Journal of Physical Chemistry B AD - Department of Physical Chemistry and the Fritz Haber Research Center, The Hebrew University, Jerusalem 91904, Israel, Department of Physics, North Dakota State University, Fargo, North Dakota 58105-5566 EP - 6996 TI - Modulation of the Spontaneous Curvature and Bending Rigidity of Lipid Membranes by Interfacially Adsorbed Amphipathic Peptides VL - 112 SP - 6988 KW - 2009_nserc_usra KW - lipid_membrane KW - phys_chem AU - Zemel, Assaf AU - Ben-Shaul, Avinoam AU - May, Sylvio PY - 2008/06/01/ UR - http://dx.doi.org/10.1021/jp711107y ER -