Adsorption-induced conformational changes in protein diffusion-aggregation surface assemblies.
Two-dimensional rigid colloid aggregation models may be applied to protein layers when no large conformational change is involved. Yet, following adsorption, several proteins undergo a conformational transition that may be involved in aggregative structures. Our focus here is how a conformational change might influence surface clustering in a diffusion-aggregation model. We propose a model including diffusion, aggregation, and unfolding of proteins that are randomly adsorbed onto a surface. Our model allows simulating the case where protein-protein interaction favors unfolding and the case where this interaction prevents it. We study the effect of a simple disk-to-rod unidirectional unfolding and investigate the morphology of the resulting clusters in the diffusion- and reaction-limited regimes. A rich variety of structures is produced, with fractal dimension differing from that in universal diffusive aggregation models. Increasing unfolding probability shifts the system from the neighbor-induced to the neighbor-prevented unfolding regime. The intermediate structures that arise from our model could be helpful in understanding the assembly of different observed protein structures.
Pellenc
Delphine
D
ERRMECe, Universite de Cergy-Pontoise, 2 avenue Adolphe Chauvin, 95302 Pontoise Cedex, France.
Gallet
Olivier
O
Berry
Hugues
H
D000327:Adsorption; D003198:Computer Simulation; D003460:Crystallization / Q000379:methods; D003461:Crystallography / Q000379:methods*; D004058:Diffusion; D008956:Models, Chemical; D008958:Models, Molecular; D046912:Multiprotein Complexes / Q000737:chemistry* / Q000648:ultrastructure*; D011485:Protein Binding; D011487:Protein Conformation; D011506:Proteins / Q000737:chemistry* / Q000648:ultrastructure*; D013499:Surface Properties
D046912:Multiprotein Complexes; D011506:Proteins