Conformations and dynamics of adsorbed protein-like chains

Abstract

Conformations and dynamics of adsorbed protein-like chains are investigated by using Monte Carlo simulation based on the modified orientation-dependent monomer–monomer interaction (ODI) model. The chain size and shape of adsorbed protein-like chains, such as mean-square end-to-end distance 〈 R 2〉, mean-square radius of gyration 〈 S 2〉 xy (or 〈 S 2〉 z ), shape factors 〈 s f i * 〉 ( i = 1 , 2 , 3 ) , and 〈 δ *〉 are discussed here. At the same time, fraction of adsorbed segment f a and average orientation of bond 〈 P 2(cos θ)〉 are also investigated. The adsorbed protein-like chains trend to be more flat when adsorption interaction energy becomes strong. Different kinds of interactions (such as contact interaction, sheet interaction, spin–spin interaction, helical interaction, and adsorbed interaction) are considered in detail. Dynamics of adsorbed protein-like chains are investigated by calculating their diffusion coefficients, and we find that there exist the relationships of D x y ∼ N − γ x y and D z ∼ N − γ z , and the values of γ xy and γ z are 4–5 times larger than that of general self-avoiding walk (SAW) chains. These investigations may provide some insights into adsorption of proteins.