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Article
Binding of Alpha-Crystallin to Cortical and Nuclear Lens Lipid Membranes Derived from a Single Lens
International Journal of Molecular Sciences
  • Raju Timsina, Boise State University
  • Samantha Wellisch, Boise State University
  • Dieter Haemmerle, Boise State University
  • Laxman Mainali, Boise State University
Document Type
Article
Publication Date
10-1-2022
Disciplines
Abstract

Several studies reported that α-crystallin concentrations in the eye lens cytoplasm decrease with a corresponding increase in membrane-bound α-crystallin with age and cataracts. The influence of the lipid and cholesterol composition difference between cortical membrane (CM) and nuclear membrane (NM) on α-crystallin binding to membranes is still unclear. This study uses the electron paramagnetic resonance (EPR) spin-labeling method to investigate the α-crystallin binding to bovine CM and NM derived from the total lipids extracted from a single lens. Compared to CMs, NMs have a higher percentage of membrane surface occupied by α-crystallin and binding affinity, correlating with less mobility and more order below and on the surface of NMs. α-Crystallin binding to CM and NM decreases mobility with no significant change in order and hydrophobicity below and on the surface of membranes. Our results suggest that α-crystallin mainly binds on the surface of bovine CM and NM and such surface binding of α-crystallin to membranes in clear and young lenses may play a beneficial role in membrane stability. However, with decreased cholesterol content within the CM, which mimics the decreased cholesterol content in the cataractous lens membrane, α-crystallin binding increases the hydrophobicity below the membrane surface, indicating that α-crystallin binding forms a hydrophobic barrier for the passage of polar molecules, supporting the barrier hypothesis in developing cataracts.

Creative Commons License
Creative Commons Attribution 4.0 International
Citation Information
Raju Timsina, Samantha Wellisch, Dieter Haemmerle and Laxman Mainali. "Binding of Alpha-Crystallin to Cortical and Nuclear Lens Lipid Membranes Derived from a Single Lens" International Journal of Molecular Sciences (2022)
Available at: http://works.bepress.com/laxman-mainali/28/