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The effect of dextran on subunit exchange of the molecular chaperone aA-crystallin

Journal Article


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Abstract


  • ñ-Crystallin, a member of small heat shock protein (sHsp) family, is comprised of ñA and ñB subunits and acts as a molecular chaperone by interacting with unfolding proteins to prevent their aggregation. The ñA-crystallin homopolymer consists of 30-40 subunits that are undergoing dynamic exchange. ñ-Crystallin and ñA-crystallin are poorer chaperones in the presence of the crowding agent, dextran. Using fluorescence resonance energy transfer, it is shown that the ñA-crystallin subunit exchange rate strongly increased with temperature. Binding of reduced ovotransferrin to ñA-crystallin markedly decreases the rate of subunit exchange, as does the presence of dextran. In addition, in the presence of dextran the effect of reduced ovotransferrin on decreasing the rate of subunit exchange of ñA-crystallin is stronger than in the absence of dextran. Under the conditions of molecular crowding, the ñA-crystallin subunit exchange rate is not temperature-dependent. The exchange rate of ñA-crystallin subunits correlates with its chaperone efficiency i.e. the variation in chaperone ability of ñA-crystallin increases with temperature. However, in the presence of dextran the temperature dependence of the chaperone action of ñA-crystallin is eliminated.

Authors


  •   Ghahghaei, Arezou (external author)
  •   Rekas, Agata (external author)
  •   Price, William E.
  •   Carver, John A. (external author)

Publication Date


  • 2007

Citation


  • Ghahghaei, A., Rekas, A., Price, W. E. & Carver, J. A. (2007). The effect of dextran on subunit exchange of the molecular chaperone aA-crystallin. BBA - Proteins and Proteomics, 1774 (1), 102-111.

Scopus Eid


  • 2-s2.0-33845967487

Ro Full-text Url


  • http://ro.uow.edu.au/cgi/viewcontent.cgi?article=1148&context=scipapers

Ro Metadata Url


  • http://ro.uow.edu.au/scipapers/131

Number Of Pages


  • 9

Start Page


  • 102

End Page


  • 111

Volume


  • 1774

Issue


  • 1

Abstract


  • ñ-Crystallin, a member of small heat shock protein (sHsp) family, is comprised of ñA and ñB subunits and acts as a molecular chaperone by interacting with unfolding proteins to prevent their aggregation. The ñA-crystallin homopolymer consists of 30-40 subunits that are undergoing dynamic exchange. ñ-Crystallin and ñA-crystallin are poorer chaperones in the presence of the crowding agent, dextran. Using fluorescence resonance energy transfer, it is shown that the ñA-crystallin subunit exchange rate strongly increased with temperature. Binding of reduced ovotransferrin to ñA-crystallin markedly decreases the rate of subunit exchange, as does the presence of dextran. In addition, in the presence of dextran the effect of reduced ovotransferrin on decreasing the rate of subunit exchange of ñA-crystallin is stronger than in the absence of dextran. Under the conditions of molecular crowding, the ñA-crystallin subunit exchange rate is not temperature-dependent. The exchange rate of ñA-crystallin subunits correlates with its chaperone efficiency i.e. the variation in chaperone ability of ñA-crystallin increases with temperature. However, in the presence of dextran the temperature dependence of the chaperone action of ñA-crystallin is eliminated.

Authors


  •   Ghahghaei, Arezou (external author)
  •   Rekas, Agata (external author)
  •   Price, William E.
  •   Carver, John A. (external author)

Publication Date


  • 2007

Citation


  • Ghahghaei, A., Rekas, A., Price, W. E. & Carver, J. A. (2007). The effect of dextran on subunit exchange of the molecular chaperone aA-crystallin. BBA - Proteins and Proteomics, 1774 (1), 102-111.

Scopus Eid


  • 2-s2.0-33845967487

Ro Full-text Url


  • http://ro.uow.edu.au/cgi/viewcontent.cgi?article=1148&context=scipapers

Ro Metadata Url


  • http://ro.uow.edu.au/scipapers/131

Number Of Pages


  • 9

Start Page


  • 102

End Page


  • 111

Volume


  • 1774

Issue


  • 1