Biophysical Society Thematic Meeting| Lima 2019

Revisiting the Central Dogma of Molecular Biology at the Single-Molecule Level

Poster Abstracts

2-POS Board 2 MD SIMULATIONS TO EXPLORE THE CX26 CONNEXON EMBEDDED INTO A POPC BILAYER Juan M.R. Albano 1,2 ; Gabriel E Jara 3 ; Maria Laura Fernandez 1,4 ; Julio C Facelli 5 ; Marta B Ferraro 1,2 ; Monica Pickholz 1,2 ; 1 Universidad de Buenos Aires, Fisica, Buenos Aires, Argentina 2 Instituto de Fisica de Buenos Aires-UBA-CONICET, Fisica, Buenos Aires, Argentina 3 Univeristy of Campinas, Chemestry, Campinas, Brazil 4 Instituto de Fisica del Plasma-UBA-CONICET, Fisica, Buenos Aires, Argentina 5 University of Utah, Biomedical Informatics, Salt Lake City, UT, USA GAP junctions provide a communication pathway between adjacent cells. They are formed by paired connexons that reside in the plasma membrane of their respective cell and their activity could be modulated by the bilayer composition. In this work, we studied the dynamic behavior of a Cx26 embedded in a POPC lipid bilayer, focusing on two factors: membrane protein interaction and ion flux though the connexon pore. We analyzed extensive atomistic Molecular Dynamics simulations for two different conditions: with and without calcium ions. We found lipid pockets surrounding the Cx26 but we did not find specific interactions with the protein, suggesting entropic effects. Furthermore, the shape and electrostatic properties of the Cx26 were also characterized taking special attention to the pore region. With these calculations, we were able to identify and explain differential chlorine flux through the pore for each system.

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