RESUMO
Searching through and conducting Monte Carlo folding simulations on 10(6) different 27 mer sequences, we have selected a prionlike lattice model whose energy spectrum and folding properties demonstrate characteristic prion behavior. The energetic competition and structural partition between two closely spaced energy minima yield unique kinetic and thermodynamic properties that can be qualitatively compared with experimental results. Folding simulations indicate that the probability of reaching the first excited state from a denatured random conformation is much higher than the probability of reaching the global energy-minimum state.
Assuntos
Príons/química , Fenômenos Biofísicos , Biofísica , Cinética , Modelos Moleculares , Método de Monte Carlo , Ligação Proteica , Conformação Proteica , Dobramento de Proteína , Termodinâmica , Fatores de TempoRESUMO
We examine the conformational properties of a random copolymer, containing a disordered hydrophobic/hydrophilic sequence of monomers, in the presence of a hydrophobic potential well. The model can be used to understand the structural properties of the adsorption of a protein molecule at a lipid-bilayer membrane, and the properties of a random copolymer at the surfaces of a microphase-separated layered polymer structure. Using a trial-potential treatment we demonstrate that a mainly hydrophilic chain may localize on the surface of the bilayer and that a mainly hydrophobic chain may have two typical conformations: localization on the surface or complete adsorption inside the two surfaces.