Estudio físico-químico del efecto de confinamiento de dos capas de fosfolípidos con ADN, mediante grano grueso

Abstract

The present research studies the physical-chemical properties of the confinement of a phospholipid bilayer with DNA. For the molecular simulation of this system, coarse grain was used, making use of the Fortran and Monte Carlo computational package. The system was formed by a plane X parallel to the Z=0 axis with dimensions 120x120x160 Angstrom, a cylinder parallel to the axis and of radius R=10.5 Angstrom and the medium, this means that the layers of phospholipids, DNA and water respectively. The plane and the cylinder have the same dielectric constant of 78.5 and temperature of T= 298 K and are immesed in a primitive model restricted 1:1 in the concentrations of 0.15 mol/l, 0.015 mol/l and 0.0015 mol/l with distance values from the plane to the cylinder of 1, 4, 7, 12, and 14 Angstrom and plane loading -0.2C/m2, -0.02C/m2 and -0.002C/m2. The number of settings for good statistics depended on the reproducibility of the results against changes in intrinsic parameters of concentration, plane charge, ion type and distance value from the plane to the cylinder. To make the system neutral, additional anions are added and the formalism of Ewald´s sums is used to cope with Coulomb interactions. When the surface charge density increased, this means that there is a high concentration of salts, a double electric layer was formed producing the invesion of charges and overcharges by an absorption process. In this context the cationic ions behave as anionic ions so the latter were attracted to the plane. It is recommended to advance the study for divalent electrolytes and to check the phenomenon of reverse charge.