AVS 49th International Symposium
    Biomaterials Monday Sessions
       Session BI-MoM

Paper BI-MoM3
Molecular Simulation Studies of Orientation of Antibodies Adsorbed on Charged Surfaces

Monday, November 4, 2002, 9:00 am, Room C-201

Session: Theoretical Studies of Biosurfaces/Biotribology and Biorheology
Presenter: S. Jiang, University of Washington
Authors: J. Zhou, University of Washington
J. Zheng, University of Washington
S. Jiang, University of Washington
Correspondent: Click to Email
Antibodies have found many applications in biotechnology and clinical medicine, including diagnostic assays, environmental testing, and process monitoring. It is well-known that Fab fragment of an antibody can bind its antigen with a very high specificity. Therefore, it is desirable to control the antibody orientation for immunoassay applications. In this work, Monte Carlo simulations are performed to study and predict the adsorption and orientation of antibodies as a function of surface and solution properties using hierarchical models, a simplified Y-shape 12-bead model antibody, a united-residue model, and an all-atom model. For all these three models, simulation results show that higher surface charge density and lower solution ionic strength favor narrower orientation distribution of adsorbed antibodies. Simulation results further show preferred antibody orientation under controlled surface and solution conditions, which are verified by our SPR and ToF-SIMS experiments. For the 12-bead model, it allows us to quickly map out the general trends of the orientation behavior of antibodies on surfaces. For the residue model we developed, more detailed residue-distribution information of antibody near surfaces can be achieved. For the all-atom model, the conformation change of an adsorbed antibody was obtained with a proposed hybrid method. The fundamental understanding of antibodies on surfaces of this work will facilitate the effort to develop better biosensors.