Membrane Tubulation in Lipid Vesicles Triggered by the Local Application of Calcium Ions
Journal article, 2017

Experimental and theoretical studies on ion-lipid interactions predict that binding of calcium ions to cell membranes leads to macroscopic mechanical effects and membrane remodeling. Herein, we provide experimental evidence that a point source of Ca2+ acting upon a negatively charged membrane generates spontaneous curvature and triggers the formation of tubular protrusions that point away from the ion source. This behavior is rationalized by strong binding of the divalent cations to the surface of the charged bilayer, which effectively neutralizes the surface charge density of outer leaflet of the bilayer. The mismatch in the surface charge density of the two leaflets leads to nonzero spontaneous curvature. We probe this mismatch through the use of molecular dynamics simulations and validate that calcium ion binding to a lipid membrane is sufficient to generate inward spontaneous curvature, bending the membrane. Additionally, we demonstrate that the formed tubular protrusions can be translated along the vesicle surface in a controlled manner by repositioning the site of localized Ca2+ exposure. The findings demonstrate lipid membrane remodeling in response to local chemical gradients and offer potential insights into the cell membrane behavior under conditions of varying calcium ion concentrations.

Author

Baharan Ali Doosti

Chalmers, Chemistry and Chemical Engineering, Chemistry and Biochemistry

W. Pezeshkian

University of Southern Denmark

D. S. Bruhn

University of Southern Denmark

J. H. Ipsen

University of Southern Denmark

H. Khandelia

University of Southern Denmark

Gavin Jeffries

Chalmers, Chemistry and Chemical Engineering, Chemistry and Biochemistry

Tatsiana Lobovkina

Chalmers, Chemistry and Chemical Engineering, Chemistry and Biochemistry

Langmuir

07437463 (ISSN) 15205827 (eISSN)

Vol. 33 41 11010-11017

Areas of Advance

Nanoscience and Nanotechnology

Subject Categories

Physical Chemistry

DOI

10.1021/acs.langmuir.7b01461

PubMed

28910109

More information

Latest update

9/6/2018 1