Abstract:

The goal of the present work is to study theor. the structure of water inside the water cylinder of the inverse hexagonal mesophase (HII) of glyceryl monooleate (monoolein, GMO), using the method of mol. dynamics. To simplify the computational model, a fixed structure of the GMO tube is maintained. The nonstd. cylindrical geometry of the system required the development and application of a novel method for obtaining the starting distribution of water mols. A predictor-corrector schema is employed for generation of the initial d. of water. Mol. dynamics calcns. are performed at const. vol. and temp. (NVT ensemble) with 1-dimensional periodic boundary conditions applied. During the simulations the lipid structure is kept fixed, while the dynamics of water is unrestrained. Distribution of hydrogen bonds and d. as well as radial distribution of water mols. across the water cylinder show water structure deep in the cylinder (∼6 \AA below the GMO heads). The obtained results may help understanding the role of water structure in the processes of insertion of external mols. inside the GMO/water system. The present work has a semi-quant. character and it should be considered as the initial stage of more comprehensive future theor. studies. (c) 2012 American Institute of Physics. [on SciFinder(R)]