Calcium enhances binding of Aβ monomer to DMPC lipid bilayer.

ABSTRACT: Using isobaric-isothermal replica-exchange molecular dynamics and the all-atom explicit-solvent model, we studied the equilibrium binding of Aβ monomers to a zwitterionic dimyristoylphosphatidylcholine (DMPC) bilayer coincubated with calcium ions. Using our previous replica-exchange molecular dynamics calcium-free simulations as a control, we reached three conclusions. First, calcium ions change the tertiary structure of the bound Aβ monomer by destabilizing several long-range intrapeptide interactions, particularly the salt bridge Asp(23)-Lys(28). Second, calcium strengthens Aβ peptide binding to the DMPC bilayer by enhancing electrostatic interactions between charged amino acids and lipid polar headgroups. As a result, Aβ monomer penetrates deeper into the bilayer, making disorder in pro

SUBMITTER: Lockhart C 

PROVIDER: S-EPMC4390832 | biostudies-literature | 2015 Apr

REPOSITORIES: biostudies-literature