Structured globules with twisted arrangement of helical blocks: Computer simulation

This report reveals the influence of local helical structure on the globular morphology. For this purpose we performed molecular dynamics simulations of coil-globule transition in alternating multi-block copolymer of helical and flexible blocks. The blocks were composed of identical beads and were equal in length. It was found that in poor solvent the macromolecules form structured globules, with regions mostly composed of either helical or flexible blocks. The morphology of the globules depends on the block length and the stiffness of the helical blocks. In the helix-rich regions the blocks have cholesteric-like arrangement, with the neighboring blocks aligned locally at a non-zero preferential skew angle, similar to the wide-spread packing motifs of biological macromolecules.

Automated summary

This study investigates the influence of local helical structure on the globular morphology in copolymers. Molecular dynamics simulations reveal that in a poor solvent environment, structured globules are formed by alternating helical and flexible blocks. The morphology of the globules is determined by the length and stiffness of the helical blocks.