AVS 53rd International Symposium
    Biomaterial Interfaces Wednesday Sessions
       Session BI-WeM

Paper BI-WeM5
Transcending the Time-Domain in Protein Adsorption Simulations

Wednesday, November 15, 2006, 9:20 am, Room 2014

Session: Bio-interfacial Modification and Bio-Immobilization I (Honoring Marcus Textor, ETH-Zürich for Substantial Contributions to the Field)
Presenter: R.A. Latour, Clemson University
Authors: R.A. Latour, Clemson University
Y. Sun, Clemson University
Correspondent: Click to Email
Although very important, the ability to predict and control the bioactive state of adsorbed or tethered proteins remains a major challenge in the field of biomaterials. While molecular modeling methods have great potential to help understand protein-surface interactions, methods must be specifically developed for this application. Two of the most important problems that must be addressed are the force field problem and the sampling problem. The force field problem relates to the design of the energy function and its parameters to ensure that atoms of a given system interact with one another in a realistic manner during a simulation. The sampling problem relates to the need to sample molecular events over timeframes that extend far beyond those that are capable of being reached using standard molecular dynamics methods. The objective of this research is to develop computational methods to address both of these issues, with a focus on the application of an advanced sampling method called replica-exchange molecular dynamics (REMD). An REMD simulation transcends the time-domain problem by enabling a Boltzmann-weighted ensemble of states to be generated, thus providing simulation results that should be directly comparable to experimental results for an equilibrated system. In this study, REMD simulations have been conducted to simulate lysozyme adsorption on a hydrophobic surface using a modified CHARMM force field with implicit solvation. The REMD simulations predict five different predominant configurations of lysozyme when adsorbed on this surface. Matched experimental studies are currently being conducted to enable the accuracy of the simulation results to be assessed.