Study of subunit interactions of alpha A- and alpha B-crystallins and the effects of gamma-irradiation on their interactions by surface plasmon resonance

Biochim Biophys Acta. 2008 Nov;1784(11):1507-13. doi: 10.1016/j.bbapap.2008.06.010. Epub 2008 Jun 24.

Abstract

Alpha-crystallin, a major protein of mammalian lens, consists of two subunits, alpha A-crystallin and alpha B-crystallin. They interact to form an aggregate and play a prominent role in the maintenance of lens transparency. We evaluated the interaction between these subunits via surface plasmon resonance (SPR) using four combinations of immobilized protein and analyte: 1) AA: alpha A-crystallin was ligand immobilized onto the sensor and alpha A-crystallin was passed over the ligand, 2) AB: ligand - alpha A-crystallin, analyte - alpha B-crystallin, 3) BB: ligand - alpha B-crystallin, analyte- alpha B-crystallin, 4) BA: ligand - alpha B-crystallin, analyte - alpha A-crystallin. The order of rate of dissociation was AA approximately BA>BB approximately AB. We also examined the dissociation of gamma irradiated alpha A- and alpha B-crystallins. As radiation dose increased, so did the dissociation rate of all of the crystallins. The order of rate of dissociation of irradiated crystallins was BB>AB approximately BA>AA. The results indicate that BB is the most susceptible to gamma-irradiation and that alpha B-crystallin forms a more stable aggregate than alpha A-crystallin under normal conditions. However, when alpha B is irradiated the aggregate becomes unstable.

Publication types

  • Research Support, Non-U.S. Gov't

MeSH terms

  • Dose-Response Relationship, Radiation
  • Gamma Rays*
  • Humans
  • Protein Binding / radiation effects
  • Protein Subunits / metabolism
  • Protein Subunits / radiation effects
  • Recombinant Proteins / isolation & purification
  • Recombinant Proteins / metabolism
  • Surface Plasmon Resonance*
  • alpha-Crystallin A Chain / chemistry
  • alpha-Crystallin A Chain / isolation & purification
  • alpha-Crystallin A Chain / metabolism*
  • alpha-Crystallin A Chain / radiation effects
  • alpha-Crystallin B Chain / chemistry
  • alpha-Crystallin B Chain / isolation & purification
  • alpha-Crystallin B Chain / metabolism*
  • alpha-Crystallin B Chain / radiation effects

Substances

  • Protein Subunits
  • Recombinant Proteins
  • alpha-Crystallin A Chain
  • alpha-Crystallin B Chain