title: Increased Binding of Calcium Ions at Positively Curved Phospholipid Membranes.
abstract: Calcium ion is the ubiquitous messenger in cells and plays a key role in neuronal signaling and fusion of synaptic vesicles. These vesicles are typically ∼20-50 nm in diameter, and thus their interaction with calcium ions cannot be modeled faithfully with a conventional flat membrane bilayer setup. Within our newly developed molecular dynamics simulations setup, we characterize here interactions of the calcium ion with curved membrane interfaces with atomistic detail. The present molecular dynamics simulations together with time-dependent fluorescence shift experiments suggest that the mode and strength of interaction of calcium ion with a phospholipid bilayer depends on its curvature. Potential of mean force calculations demonstrate that the binding of calcium ion to the positively curved side of the bilayer is significantly stronger compared with that to a flat membrane.
authors.affiliation: Institute of Organic Chemistry and Biochemistry, Academy of Sciences of the Czech Republic , Flemingovo nám. 2, 16610 Prague 6, Czech Republic.|Faculty of Pharmacy, University of Helsinki , Viikinkaari 5E, Helsinki 00014, Finland.
authors.forename: Aniket
authors.initials: A
authors.lastname: Magarkar
authors.affiliation: J. Heyrovský Institute of Physical Chemistry, Academy of Sciences of the Czech Republic , v.v.i., Dolejškova 3, CZ-182 23 Prague, Czech Republic.
authors.forename: Piotr
authors.initials: P
authors.lastname: Jurkiewicz
authors.affiliation: Institute of Organic Chemistry and Biochemistry, Academy of Sciences of the Czech Republic , Flemingovo nám. 2, 16610 Prague 6, Czech Republic.|Institut für Physikalische und Theoretische Chemie, Universität Regensburg , 93040 Regensburg, Germany.
authors.forename: Christoph
authors.initials: C
authors.lastname: Allolio
authors.affiliation: J. Heyrovský Institute of Physical Chemistry, Academy of Sciences of the Czech Republic , v.v.i., Dolejškova 3, CZ-182 23 Prague, Czech Republic.
authors.forename: Martin
authors.initials: M
authors.lastname: Hof
authors.affiliation: Institute of Organic Chemistry and Biochemistry, Academy of Sciences of the Czech Republic , Flemingovo nám. 2, 16610 Prague 6, Czech Republic.|Department of Physics, Tampere University of Technology , P.O. Box 692, FI-33101 Tampere, Finland.
authors.forename: Pavel
authors.identifier: http://orcid.org/0000-0002-6892-3288
authors.initials: P
authors.lastname: Jungwirth
mesh_terms: D002118:Calcium / Q000737:chemistry*; D007477:Ions / Q000737:chemistry; D008051:Lipid Bilayers / Q000737:chemistry*; D008081:Liposomes / Q000737:chemistry; D008566:Membranes; D008567:Membranes, Artificial; D056004:Molecular Dynamics Simulation; D010743:Phospholipids / Q000737:chemistry*; D014867:Water / Q000737:chemistry
chemical_list: D007477:Ions; D008051:Lipid Bilayers; D008081:Liposomes; D008567:Membranes, Artificial; D010743:Phospholipids; D014867:Water; D002118:Calcium