title: Understanding the Hofmeister effect in interactions between chaotropic anions and lipid bilayers: molecular dynamics simulations.
abstract: A set of all-atom molecular dynamics simulations have been performed to better understand critical phenomena regarding a Hofmeister series of anions and lipid bilayers. The simulations isolate the effect of anion size and show clear differences in the interactions with the dipolar phoshpatidylcholine headgroup. Cl- anions penetrate into the headgroup region of the bilayer, but the simulations confirm theories which predict that larger anions penetrate more deeply, into a more heterogeneous and hydrophobic molecular region. That anion size leads to such differences in partitioning in the bilayer provides atomic-level support to hypotheses inspired by several experimental studies. The ability of larger anions to bury deep within the bilayer is correlated with a less well-structured hydration shell, shedding of which upon penetration incurs a smaller penalty for the larger anions than for Cl-.
authors.affiliation: Department of Biomedical Engineering, Johns Hopkins University, School of Medicine, 725 North Wolfe Street, Baltimore, Maryland 21205, USA.
authors.forename: Jonathan N
authors.initials: JN
authors.lastname: Sachs
authors.forename: Thomas B
authors.initials: TB
authors.lastname: Woolf
mesh_terms: D000838:Anions / Q000737:chemistry*; D003198:Computer Simulation; D057927:Hydrophobic and Hydrophilic Interactions; D008051:Lipid Bilayers / Q000737:chemistry*; D008956:Models, Chemical; D008958:Models, Molecular; D008968:Molecular Conformation; D010713:Phosphatidylcholines / Q000737:chemistry
chemical_list: D000838:Anions; D008051:Lipid Bilayers; D010713:Phosphatidylcholines; C028694:1-palmitoyl-2-oleoylphosphatidylcholine