title: Denaturation of proteins near polar surfaces.
abstract: All-atom molecular dynamics simulations for proteins placed near a model mica surface indicate existence of two types of evolution. One type leads to the surface-induced unfolding and the other just to a deformation. The two behaviors are characterized by distinct properties of the radius of gyration and of a novel distortion parameter that distinguishes between elongated, globular, and planar shapes. They also differ in the nature of their single site diffusion and two-site distance fluctuations. The four proteins chosen for the studies, the tryptophan cage, protein G, hydrophobin and lyzozyme, are small to allow for a fair determination of the forces generated by the surface as the effects of finite cutoffs in the Coulombic interactions are thus minimized. When the net charge on the surface is set to zero artificially, infliction of deformation is seen to persists but no unfolding takes place. Unfolding may also be prevented by a cluster of disulfide bonds, as we observe in simulations of hydrophobin.
authors.affiliation: Institute of Physics, Polish Academy of Sciences, Aleja Lotników 32/46, 02-668 Warsaw, Poland.
authors.forename: Anna
authors.initials: A
authors.lastname: Starzyk
authors.forename: Marek
authors.initials: M
authors.lastname: Cieplak
mesh_terms: D000538:Aluminum Silicates / Q000737:chemistry; D001426:Bacterial Proteins / Q000737:chemistry; D056004:Molecular Dynamics Simulation; D009113:Muramidase / Q000737:chemistry; D011487:Protein Conformation; D011489:Protein Denaturation; D011506:Proteins / Q000737:chemistry*; D013499:Surface Properties
chemical_list: D000538:Aluminum Silicates; D001426:Bacterial Proteins; C034284:IgG Fc-binding protein, Streptococcus; D011506:Proteins; D009113:Muramidase; C011934:mica