Chaperone-like activity and hydrophobicity of alpha-crystallin

IUBMB Life. 2006 Nov;58(11):632-41. doi: 10.1080/15216540601010096.


alpha-Crystallin, a prominent member of small heat shock protein (sHsp) family and a major structural protein of the eye lens is a large polydisperse oligomer of two isoforms, alphaA- and alphaB-crystallins. Numerous studies have demonstrated that alpha-crystallin functions like a molecular chaperone in preventing the aggregation of various proteins under a wide range of stress conditions. The molecular chaperone function of alpha-crystallin is thus considered to be vital in the maintenance of lens transparency and in cataract prevention. alpha-Crystallin selectively interacts with non-native proteins thereby preventing them from aggregation and helps maintain them in a folding competent state. It has been proposed and generally accepted that alpha-crystallin suppresses the aggregation of other proteins through the interaction between hydrophobic patches on its surface and exposed hydrophobic sites of partially unfolded substrate protein. However, a quantifiable relationship between hydrophobicity and chaperone-like activity remains a matter to be concerned about. On an attentive review of studies on alpha-crystallin chaperone-like activity, particularly the studies that have direct or indirect implications to hydrophobicity and chaperone-like activity, we found several instances wherein the correlation between hydrophobicity and its chaperone-like activity is paradoxical. We thus attempted to provide an overview on the role of hydrophobicity in chaperone-like activity of alpha-crystallin, the kind of evaluation done for the first time.

Publication types

  • Research Support, Non-U.S. Gov't
  • Review

MeSH terms

  • Amino Acid Sequence
  • Animals
  • Humans
  • Hydrophobic and Hydrophilic Interactions
  • Molecular Chaperones / physiology*
  • Molecular Sequence Data
  • Protein Structure, Quaternary / drug effects
  • Sequence Alignment
  • alpha-Crystallins / chemistry*
  • alpha-Crystallins / physiology*


  • Molecular Chaperones
  • alpha-Crystallins