Swapping the Positions in a Cross-Strand Lateral Ion-Pairing Interaction between Ammonium- and Carboxylate-Containing Residues in a β-Hairpin.

摘要: Cross-strand lateral ion-pairing interactions are important for antiparallel β-sheet stability. Statistical studies suggested that swapping the position of cross-strand residues should not significantly affect interaction. Herein, we swapped ammonium- and carboxylate-containing with different side-chain lengths in a interaction β-hairpin. The peptides were analyzed by 2D-NMR. fraction folded population folding free energy derived from chemical shift data. was using double mutant cycle analysis. general trends energetics remained similar upon interacting charged residues. most stabilizing between short residues, to unswapped study. However, populations higher compared corresponding peptides. Furthermore, subtle differences observed, likely due “unleveled” relative positioning created inherent right-handed twist structure. These results be useful developing functional rely on across β-strands.