Study of Protein-Protein Interactions in Septin Assembly: Multiple amphipathic helix domains cooperate in binding to the lipid membrane
Fig 4
Salt bridge formation between charged amino acids promotes peptide-peptide interactions.
(A) Contact map showing intra- and inter-peptide contacts. The zoomed-in inter-peptide region highlights a salt bridge between charged residues R4 and E21. The N-terminal of the floating peptide preferentially interacts with the ending region of the AH domain of the bound peptide, indicating an antiparallel peptide orientation. (B) The domain-based coarse-grained contact maps averaged over all replicas in different time windows show two peptides interacting in an anti-parallel configuration that reaches a steady state. (C) Simulation snapshot showing multiple salt bridges formed between charged residues of the floating and bound peptide. Basic residues are shown in blue, acidic in red, polar in green, and hydrophobic in magenta. (D) number of inter-peptide contacts between residue pairs of the floating and bound peptides. The majority of contacts involve charged residues. (E) Time evolution of residue pair distances for the top-ranked salt bridge contacts, revealing how the two peptides interact (replica 2). R and E residues form a stable salt bridge throughout the simulation.