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Salt bridges
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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. | 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<ref>Jeffrey, George A., An introduction to hydrogen bonding, Oxford University Press, 1997. Page 192.</ref>. The center of charge of the arginine sidechain is the zeta carbon. The energetic significance of such complementary charge pairs is a complex function of the local environment. | + | A salt bridge is generally considered to exist when the centers of charge are 4 Å or less apart<ref>Jeffrey, George A., An introduction to hydrogen bonding, Oxford University Press, 1997. Page 192.</ref>. The center of charge of the arginine sidechain is the zeta carbon<ref name='GD'>PMID: 10449714</ref>. 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]]. | Putative salt bridges can be displayed by [[FirstGlance in Jmol]]. | ||
Revision as of 18:48, 3 February 2010
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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.
