Federico Elías-Wolff

arXiv2018

Structural symmetry and membrane curvature sensing

Symmetry is closely intertwined with the function, genetics, and chemical properties of multiprotein complexes. Here, we explore the relation between structural symmetry and the ability of membrane proteins to sense and induce membrane curvature, which is a key factor for modulating the shape and organization of cell membranes. Using coarse-grained simulations and elasticity theory, we show that the potential for direction-dependent membrane curvature sensing is limited to asymmetric proteins, dimers, and tetramers, and argue that one should expect this anisotropy to be strongest for dimers. Odd and higher-order symmetries strongly suppress directional curvature sensing. This classification gives a new perspective on the structure-function relation for membrane proteins, and simplifies the task of translating between molecular sensing mechanisms and their large-scale cellular consequences.

physics.bio-ph↗

arXiv2016

Anisotropic membrane curvature sensing by amphipathic peptides

Many proteins and peptides have an intrinsic capacity to sense and induce membrane curvature, and play crucial roles for organizing and remodelling cell membranes. However, the molecular driving forces behind these processes are not well understood. Here, we describe a new approach to study curvature sensing, by simulating the direction-dependent interactions of single molecules with a buckled lipid bilayer. We analyse three amphipathic antimicrobial peptides, a class of membrane-associated molecules that specifically target and destabilize bacterial membranes, and find qualitatively different sensing characteristics that would be difficult to resolve with other methods. These findings provide new insights into the curvature sensing mechanisms of amphipathic peptides and challenge existing theories of hydrophobic insertion. Our approach is generally applicable to a wide range of curvature sensing molecules, and our results provide strong motivation to develop new experimental methods to track position and orientation of membrane proteins.

physics.bio-ph↗