The amyloid β (Aβ) peptide associated with Alzheimer's disease results from processing of the amyloid precursor protein (APP) by secretases. Cleavage of APP by β-secretase produces a 99 amino acid C-terminal fragment of APP (C99) consisting of a single transmembrane (TM) helix. Simulations of C99 congeners and structural studies of C99 in surfactant micelles and lipid vesicles have shown that a...

Junhua Zhang,1 Rahul Nandkishore,2,3 and E. Rossi1 1Department of Physics, College of William and Mary, Williamsburg, Virginia 23187, USA 2Department of Physics, Massachusetts Institute of Technology, Cambridge, Massachusetts 02139, USA 3Princeton Center for Theoretical Science, Princeton University, Princeton, New Jersey 08544, USA (Received 17 January 2014; revised manuscript received 31 Marc...

Pablo San-Jose1 and Elsa Prada2 1Instituto de Ciencia de Materiales de Madrid (ICMM-CSIC), Cantoblanco, 28049 Madrid, Spain 2Departamento de Fı́sica de la Materia Condensada, Instituto de Ciencia de Materiales Nicolás Cabrera, Instituto de Fı́sica de la Materia Condensada, Universidad Autónoma de Madrid, Cantoblanco, 28049 Madrid, Spain (Received 25 April 2013; revised manuscript received 18 July...

We study the static and dynamic screening of gapped AB-stacked bilayer graphene. Unlike previous works we use the full 4-band model instead of the simplified 2-band model. We find that there are important qualitative differences between the dielectric screening function obtained using the simplified 2-band model and the 4-band model. In particular, within the 4-band model, in the presence of a ...

Recent experimental results revealed that lipid-mediated interactions due to hydrophobic forces may be important in determining the protein topology after insertion in the membrane, in regulating the protein activity, in protein aggregation and in signal transduction. To gain insight into the lipid-mediated interactions between two intrinsic membrane proteins, we developed a mesoscopic model of...

Motivated by recent experiments on bilayer polyhedra composed of amphiphilic molecules, we study the elastic bending energies of bilayer vesicles forming polyhedral shapes. Allowing for segregation of excess amphiphiles along the ridges of polyhedra, we find that bilayer polyhedra can indeed have lower bending energies than spherical bilayer vesicles. However, our analysis also implies that, co...

Antimicrobial peptides interact specifically with the membrane of a pathogen and kill the pathogen by releasing its cellular contents. Protegrin-1 (PG-1), a beta-hairpin antimicrobial peptide, is known to exist as a transmembrane monomer in a 1,2-dilauroylphosphatidylcholine (DLPC) bilayer and shows concentration-dependent oligomerization in a 1-palmitoyl-2-oleoylphosphatidylcholine (POPC) bila...