Structure and Dynamics of Aqueous Solutions Next to and between Membrane Surfaces
Abstract
The objective of our research is to investigate structural and dynamical properties of aqueous solutions next to and between surfaces of biological macromolecules, particularly membranes. The goal of our research is to understand the molecular origin of the short-range forces acting between macromolecules. These forces are usually attributed to the polarization of water at the interface, and therefore are called hydration forces. But in a recent article Israelachvili and Wennerstrom challenged this idea. According to I&W, the hydration force is due to the entropic repulsion of molecular groups that are thermally excited to protrude from the surfaces. I&W claim that the monotonically repulsive hydration forces are smeared-out oscillatory forces, due to the thermal motion of the head-groups. We use the method of molecular dynamics computer simulation in our investigation. Since phospholipid molecules are not included in a standard field force of simulation packages such as GROMOS, or AMBER or CHARMm we had to obtain potential parameters ourselves. This was done through the use of the quantum chemistry package Gaussian-88. We have also made appropriate changes in the AMBER code, that allowed us to perform molecular dynamics of a phospholipid bilayer. In addition we write our own programs to perform analysis of the data.
Document Details
- Document Type
- Technical Report
- Publication Date
- Jun 26, 1990
- Accession Number
- ADA223755
Entities
People
- Max L. Berkowitz
Organizations
- University of North Carolina at Chapel Hill