Equilibrium and kinetics at the coil-to-globule transition of star and comb heteropolymers in infinitely dilute solutions

By means of continuous space Monte Carlo simulation, we study conformationa l structures formed by star and comb heteropolymers during kinetics of fold ing from the coil to the globule, as well as the corresponding equilibrium states on going from the good to the poor solution. Particular examples of combs with hydrophobic backbone and hydrophilic side-groups (and vice versa ), as well as stars with flexible and semi-stiff arms are studied. It is in teresting to note that star-like conformations naturally appear for a comb polymer with a strongly hydrophobic backbone. We emphasise the crucial diff erence in the spatial distribution of hydrophobic and hydrophilic monomers within the globular states for the above mentioned two types of combs, In c ase of stars, the non-equilibrium states during kinetics of the coil-to-glo bule transition correspond to formation of localised pearls within flexible arms, whereas semi-stiff arms prefer to join with each other remaining ess entially extended. These studies present natural extension of our previous works on the equilibrium and kinetic properties of linear and ring heteropo lymers based on the Gaussian self-consistent method and lattice Monte Carlo technique. However, in studying polymers with more nontrivial topology con tinuous space simulation has some essential advantages. (C) 2001 Elsevier S cience B.V. All rights reserved.