Aggregation of amphipathic peptides at an aqueous-organic interface using coarse-grained simulations

作者：Latshaw David C II; Randolph Theodore W; Hall Carol K^*

来源：Molecular Simulation, 2017, 43(17): 1448-1458.

DOI：10.1080/08927022.2017.1319058

• Amphipathic
• monolayer
• simulation
• interface
• aggregation

The effect of an aqueous/organic interface on the folding and aggregation of amphipathic peptides is examined by applying discontinuous molecular dynamics (DMD) simulations combined with an intermediate resolution protein model, PRIME20, to a peptide/interface system. The systems contain 48 (KLLK)(4) peptides in random coil or alpha-helical conformations interacting with both strong and weak interfaces. In the absence of an interface, most of the oligomers form helical bundles, a small fraction of which convert to beta-sheets when the temperature is above the folding transition. Adding a weak interface decreases oligomer formation above the folding temperature and increases it below. Little monolayer formation is observed at the weak interface; instead reversible adsorption increases the local peptide concentration near the interface, promoting helical bundle formation in the aqueous phase below the folding temperature and beta-sheet formation above the folding temperature. Introducing a strong interface leads to irreversible adsorption, promoting formation of helical monolayers below the folding temperature and mixed beta-sheet/amorphous monolayers above the folding temperature. The (KLLK)(4) peptide is more likely to adsorb to the interface when it is in an alpha-helical conformation, as opposed to a random coil, because of its larger hydrophobic moment.

• 出版日期2017