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A2E, A Fluorophore of RPE Lipofuscin, Can Destabilize Membrane

  • Janet R. Sparrow
  • Bolin Cai
  • Young Pyo Jang
  • Jilin Zhou
  • Koji Nakanishi
Part of the Advances in Experimental Medicine and Biology book series (volume 572)

Abstract

Studies of Stargardt disease suggest a role for RPE lipofuscin in the RPE cell atrophy that characterizes macular degeneration. The best known constituent of RPE lipofuscin is the pyridinium bisretinoid, A2E (Eldred and Lasky, 1993; Parish et al., 1998). Amongst the properties of A2E that may be damaging to the RPE cell is its ability to destabilize cell membranes (Sparrow et al., 1999). A hydrophilic head group combined with a pair of hydrophobic side-arms are the structural correlates of this behavior. This amphiphilic structure accounts for the tendency of A2E to aggregate (Sakai et al., 1996; De and Sakmar, 2002), a behavior first recognized in deuterated chloroform (CDCl3), the broadening of the 1H NMR signal indicating that the protonated pyridinium moieties of A2E were closely packed within the interior of micelles while the hydrophobic chains contacted the solvent. Further evidence of the detergent-like behaviour of A2E has been revealed in experiments demonstrating the ability of A2E to induce concentration-dependent membrane leakage (Sparrow et al., 1999). In studies employing unilamellar vesicles, it has also been shown that A2E, at critical micellar concentrations, can solubilize membranes (De and Sakmar, 2002).

Keywords

Macular Degeneration Deuterated Chloroform Hydrophilic Head Group Stargardt Disease Mented Epithelial Cell 
These keywords were added by machine and not by the authors. This process is experimental and the keywords may be updated as the learning algorithm improves.

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Copyright information

© Springer Science+Business Media, Inc. 2006

Authors and Affiliations

  • Janet R. Sparrow
  • Bolin Cai
  • Young Pyo Jang
  • Jilin Zhou
  • Koji Nakanishi
    • 1
  1. 1.Departments of Ophthalmology and ChemistryColumbia UniversityNew York

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