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

Paper BI-TuP12
Molecular Simulation of Cytochrome C Adsorbed on Self-Assembled Monolayers

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

Session: Poster Session
Presenter: J. Zhou, University of Washington
Authors: J. Zhou, University of Washington
J. Zheng, University of Washington
S. Jiang, University of Washington
Correspondent: Click to Email
Cytochrome c, a membrane electron transfer protein, plays an important role not only in a wide range of basic life processes, but also in biomaterial and biosensor applications. To enable the electron transfer fast, cytochrome c should sit on the surfaces with an orientation that the heme ring close and perpendicular to surfaces. Moreover, the adsorbed cytochrome c should keep its native conformation. Self-assembled monolayers are ideal platforms for the study of protein adsorption. In this work, the orientation and conformation of cytochrome c on charged self-assembled monolayers are investigated by a combined Monte Carlo and molecular dynamics simulation approach. The effects of positively and negatively charged SAMs, degree of dissociation of COOH-terminated SAM, ionic strength are examined. CHARMM force field was used to model the protein and SAM. Both implicit and explicit solvent model were used. The root mean square deviation, gyration radius, eccentricity, Ramachandran angles, heme orientation and superimposed structures of cytochrome c were calculated during the simulation. Simulation results show that desired orientation could be obtained on a negatively charged surface. The dissociation degree of the terminal group affects the conformation of adsorbed protein. This work sheds light on the mechanism of the orientation and conformation of adsorbed proteins at the molecular level, and would be useful for the design and development of biosensors and biomaterials.