AVS 50th International Symposium
    Biomaterial Interfaces Tuesday Sessions
       Session BI-TuP

Paper BI-TuP14
Molecular Dynamics Study of Protein Adsorption on Controlled Surfaces

Tuesday, November 4, 2003, 5:30 pm, Room Hall A-C

Session: Poster Session
Presenter: J. Zheng, University of Washington
Authors: J. Zheng, University of Washington
S. Jiang, University of Washington
Correspondent: Click to Email
Surface resistance to protein adsorption is currently a subject of great interest with potential applications in many areas, including biomaterials and biosensors. Despite its importance, there has been a lack of molecular-level understanding of protein interactions with surfaces and the mechanism of resistance to protein adsorption remains a problem to be solved. It is well known that SAMs presenting oligo (ethylene glycol) (OEG) groups, such as S(CH2)m-(EG)nOH or -(EG)nOCH3 resist the adsorption of proteins. The molecular-level understanding of protein resistance to surfaces is needed in order to provide insights of non-fouling mechanism. In the work, we investigate interactions of protein (e.g., lysozyme) with OEG SAM (inner) surfaces using a combined Monte Carlo and molecular dynamics simulation approach in the presence of explicit water molecules. The CHARMM (version 27), an all-atom potential force field, was used to model the protein and methyl terminated SAMs. The TIP3P potential was used to describe water interactions. For the OEG terminated SAMs, we used a SJY model that reproduces very well the helix structure of OEG tails. Results from inert surfaces will be compared with those from methyl terminated SAM surfaces. The behavior of water at protein/SAM interfaces is characterized by self-diffusion coefficient, order parameter, hydrogen bonding, and radial distribution. In these simulations the effects of surface (charge, hydrophobicity, and defect), solvent, pH, and ion strength will be taken into account. Results from this work will shed a light on non-fouling mechanism at the atomic-scale level and guide the design of better biocompatible materials and biosensors.