First time at Proteopedia? Click on the green links, they change the 3D image. Click and drag the molecules. Proteopedia is a 3D, interactive encyclopedia of proteins, RNA, DNA and other molecules. With a free user account, you can edit pages in Proteopedia. Visit the Main Page to learn more.

Salt bridges

From Proteopedia

Jump to: navigation, search

Salt bridge between retinoic acid(-) and arg131(+) in 1cbr.

In proteins, salt bridges occur between amino acid side-chains with opposite positive or negative full-electron charges, namely, (at neutral pH) Glu- or Asp- vs. Arg+ or Lys+. They may also occur between ionized organic ligands, such as acetylcholine+ (or example at right: 1cbr), or inorganic ions, such as K+ or Cl-, and amino acid side-chains.

A salt bridge is generally considered to exist when the centers of charge are 4 Å or less apart[1]. The center of charge of the arginine sidechain is the zeta carbon[2]. The energetic significance of such complementary charge pairs is a complex function of the local environment.

Putative salt bridges can be displayed by FirstGlance in Jmol.

References

  1. ↑ Jeffrey, George A., An introduction to hydrogen bonding, Oxford University Press, 1997. Page 192.
  2. ↑ Gallivan JP, Dougherty DA. Cation-pi interactions in structural biology. Proc Natl Acad Sci U S A. 1999 Aug 17;96(17):9459-64. PMID:10449714

Proteopedia Page Contributors and Editors (what is this?)

Eric Martz

Retrieved from "http://proteopedia.org/wiki/index.php/Salt_bridges"
Personal tools