Adsorption Behavior of Homogeneous Model Proteins On Hydrophobic Surfaces From Dissipative Particle Dynamics Simulations

Wednesday, November 10, 2010: 4:55 PM
Grand Ballroom H (Salt Palace Convention Center)
Kristin Patterson1, Martin Lisal2 and Coray M. Colina1, (1)Department of Materials Science and Engineering, Pennsylvania State University, University Park, PA, (2)E. Hala Laboratory of Thermodynamics, Academy of Sciences of the Czech Republic, Prague, Czech Republic

Protein adsorption behavior has been a topic of intense research and great debate in the field of biomaterials surface science for decades. Experimentalists have studied the adsorption behavior of hundreds of different proteins on varying surfaces including metals[1], ceramics[2], glasses[3], synthetic polymers[4], natural polymers[5,6], and atop other proteins. Despite this extensive library of research, a fundamental understanding of protein adsorption remains uncertain. In this work, we approach the problem with the tools of molecular simulations. We utilize the mesoscale simulation method of dissipative particle dynamics (DPD) to explore the adsorption behavior of model proteins in solution in the presence of surfaces of varying hydrophilicity. Moreover a quantitative explanation of adsorption and desorption kinetics is included.

In DPD multiple atoms or molecules are considered to be grouped into beads characterized by a center of mass, position, and momentum. The technique has been extended to biomolelcular system including vesicles[7], lipid bilayers, microtubules[8], and, in a very limited number of studies, model proteins[9,10]. Studies which have included model proteins have mostly focused on their behavior when embedded within lipid bilayers and the effect of hydrophobic mismatch. Recently, we used the DPD method to compare the adsorption behavior of large and small elongated proteins in solution in the presence of a hydrophobic surface. To the best of our knowledge, this was the first time DPD had been used to study protein adsorption.

Here [11], we compare the adsorption kinetics of systems containing multiple proteins in solution in the presence of a solid surface. In the first phase of the study, we compare systems containing homogeneous model proteins of two different sizes (small and large elongated) near surfaces ranging from lightly hydrophobic to highly hydrophobic. We find distinct differences in adsorption and desorption behavior between the small and large elongated proteins which arise from the difference in total available protein-surface bead-bead interaction. In addition, we note an inability for the large elongated proteins to desorb from the surface once adsorbed, irrespective of the degree of hydrophobicity. We also note a striking difference in the diffusion and adsorption kinetics between the two types of proteins: the small elongated proteins exhibit rapid diffusion as well as adsorption kinetics, while their larger counterparts were much slower. In the second phase, we explore the effect of initial configuration (protein position within the simulation box) on the time-to-adsorption as well as steady-state behavior.

References

1. Prime, K.L., Whitesides, G.M., Adsorption of Proteins on Surfaces Containing End-Attached Oligo(ethylene oxide): A Model System Using Self-Assembled Monolayers. J. Am. Chem. Soc. 1993, (115), 10714-10721

2. Zhu, X.D., Zhang, H.J., Fan, H.S., Li, W., Zhang, X.D., Effect of phase composition and microstructure of calcium phosphate ceramic particles on protein adsorption. Acta Biomaterialia. 2010, 1536-1541

3. Buchanan, L.A., El-Ghannam, A. Effect of bioactive glass crystallization on the conformation and bioactivity of adsorbed proteins. J. Biomed. Mat. Res. A. 2010 (93A) 537-546

4. Jeon, S.I., Lee, J.H., Andrade, J.D., De Gennes, P.G. Protein-Surface Interactions in the Presence of Polyethylene Oxide. J. Col. Int. Sci. 1990 (142) 149-158

5. Liu, P.S., Chen, Q., Wu, S.S., Shen, J., Lin, S.C. Surface modification of cellulose membranes with zwitterionic polymers for resistance to protein adsorption and platelet adhesion. 2010 (350) 387-394

6. Yang, Q., Kaul, C., Ulbricht, M. Anti-nonspecific Protein Adsorption Properties of Biomimetic Clycocalyx-like Glycopolymer Layers: Effects of Glycopolymer Chain Density and Protein Size. Langmuir. 2010 (26) 5746-5752

7. Shillcock, J. C.; Lipowsky, R., The computational route from bilayer membranes to vesicle fusion. J. Phys.: Condens. Matter 2006, 18, (28), S1191-S1219

8. Chen, Q.; Li, D. Y.; Oiwa, K., The coordination of protein motors and the kinetic behavior of microtubule - A computational study. Biophys. Chem. 2007, 129, (1), 60-69

9. Venturoli, M.; Smit, B.; Sperotto, M. M., Simulation studies of protein-induced bilayer deformations, and lipid-induced protein tilting, on a mesoscopic model for lipid bilayers with embedded proteins. Biophys. J. 2005, 88, (3), 1778-1798

10. Wu, S.; Guo, H., Dissipative particle dynamics simulation study of the bilayer-vesicle transition. Sci. China, Ser. B: Chem. 2008, 51, (8), 743-750

11. Patterson, K. P.; Lisal, M.; Colina, C. M.,Adsorption behavior of model proteins on surfaces, Fluid Phase Equilb, 2010 asap


Extended Abstract: File Not Uploaded