Anticooperativity in a Glu-Lys-Glu salt bridge triplet in an isolated α-helical peptide

Teuku M. Iqbalsyah, Andrew J. Doig

    Research output: Contribution to journalArticlepeer-review


    Salt bridges between oppositely charged side chains are well-known to stabilize protein structure, though their contributions vary considerably. Here we study Glu-Lys and Lys-Glu salt bridges, formed when the residues are spaced i, i + 4 surface of an isolated α-helix in aqueous solution. Both are stabilizing by -0.60 and -1.02 kcal/mol, respectively, when the interacting residues are fully charged. When the side chains are spaced i, i + 4, i + 8, forming a Glu-Lys-Glu triplet, the second salt bridge provides no additional stabilization to the helix. We attribute this to the inability of the central Lys to form two salt bridges simultaneously. Analysis of these salt bridges in protein structures shows that the Lys-Glu interaction is dominant, with the side chains of the Glu-Lys pair far apart. © 2005 American Chemical Society.
    Original languageEnglish
    Pages (from-to)10449-10456
    Number of pages7
    Issue number31
    Publication statusPublished - 9 Aug 2005


    Dive into the research topics of 'Anticooperativity in a Glu-Lys-Glu salt bridge triplet in an isolated α-helical peptide'. Together they form a unique fingerprint.

    Cite this