Cataract, an opacification of the eye lens caused by a loss of solubility of the crystallin proteins, is a leading cause of blindness worldwide. The overarching goal of the proposed research is to use computational modeling and a broad suite of biophysical experiments to gain new insight into cataract formation on the molecular level that could ultimately guide the development of new therapies for cataract prevention and treatment. The primary hypothesis driving the proposed research is that altered protein-protein interactions, resulting from point mutations (in the case of congenital cataract) or post- translational modifications (in the case of age-related cataract), lead to aggregation of the crystallins which, in turn, leads to loss of transparency in the lens. We propose a concerted experimental and computational investigation of protein structure, organization, and aggregation in solutions of human ?D- and ?S-crystallins. We will employ a multiscale computational modeling approach, consisting of Monte Carlo and atomistic molecular dynamics simulations, validated and refined using experimental data (NMR, light scattering, and small angle scattering), to gain molecular-scale insight into the interprotein interactions that stabilize concentrated solutions of wild-type ?D- and ?S- crystallins, or lead to the formation of insolubl aggregates in solutions of variants associated with congenital cataracts. The same approach will be applied in the first systematic computational and biophysical investigation of deamidated variants of ?S- crystallin that mimic the changes observed in age-related cataract. Once the concerted application of MC simulations, biophysical experiments, small angle scattering measurements, and solution and solid-state NMR experiments has been developed for single-component ?-crystallin solutions, the approach will be applied to the determination of a molecular-level description of the interactions between ?B-crystallins and wild-type ?-crystallin and their cataract-related variants. Thus, we will gain crucial insight into the chaperone function of the ?B-crystallins, as well as the ability of the ?B-crystallins to maintain the delicate balace of interactions that maintains the transparency of solutions of wild-type ?-crystallins.

Public Health Relevance

Cataract, an opacification of the eye lens caused by a loss of solubility of the crystallin proteins, is a leading cause of blindness worldwide. The goal of the proposed research is to gain insight into cataract formation on the molecular level that could ultimately guide the development of new therapies for cataract prevention and treatment.

Agency
National Institute of Health (NIH)
Institute
National Eye Institute (NEI)
Type
Research Project (R01)
Project #
5R01EY025328-03
Application #
9428451
Study Section
Macromolecular Structure and Function D Study Section (MSFD)
Program Officer
Araj, Houmam H
Project Start
2016-03-01
Project End
2019-02-28
Budget Start
2018-03-01
Budget End
2019-02-28
Support Year
3
Fiscal Year
2018
Total Cost
Indirect Cost
Name
University of California Irvine
Department
Microbiology/Immun/Virology
Type
Schools of Medicine
DUNS #
046705849
City
Irvine
State
CA
Country
United States
Zip Code
92617
Roskamp, Kyle W; Montelongo, David M; Anorma, Chelsea D et al. (2017) Multiple Aggregation Pathways in Human ?S-Crystallin and Its Aggregation-Prone G18V Variant. Invest Ophthalmol Vis Sci 58:2397-2405