Display Settings:


Send to:

Choose Destination
See comment in PubMed Commons below
Biochemistry. 2005 Aug 9;44(31):10449-56.

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

Author information

  • 1Faculty of Life Sciences, Jackson's Mill, The University of Manchester, P.O. Box 88, Sackville Street, Manchester M60 1QD, UK.


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 alpha-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.

[PubMed - indexed for MEDLINE]
Free PMC Article

Images from this publication.See all images (6)Free text

Figure 5
Figure 6
PubMed Commons home

PubMed Commons

How to join PubMed Commons

    Supplemental Content

    Icon for American Chemical Society Icon for PubMed Central
    Loading ...
    Write to the Help Desk