Conformations and dynamics of adsorbed protein-like chains

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 〈R2〉, mean-square radius of gyration 〈S2〉xy (or 〈S2〉z), shape factors 〈sfi*〉(i=1,2,3), and 〈δ*〉 are discussed here. At the same time, fraction of adsorbed segment fa and average orientation of bond 〈P2(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 Dxy∼N−γxyand Dz∼N−γz, and the values of γxy and γz are 4-5 times larger than that of general self-avoiding walk (SAW) chains. These investigations may provide some insights into adsorption of proteins.