Redox chemistry of lens crystallins: A system of cysteines

The nuclear region of the lens is metabolically quiescent, but it is far from inert chemically. Without cellular renewal and with decades of environmental exposures, the lens proteome, lipidome, and metabolome change. The lens crystallins have evolved exquisite mechanisms for resisting, slowing, adapting to, and perhaps even harnessing the effects of these cumulative chemical modifications to minimize the amount of light-scattering aggregation in the lens over a lifetime. Redox chemistry is a major factor in these damages and mitigating adaptations, and as such, it is likely to be a key component of any successful therapeutic strategy for preserving or rescuing lens transparency, and perhaps flexibility, during aging. Protein redox chemistry is typically mediated by Cys residues. This review will therefore focus primarily on the Cys-rich gamma-crystallins of the human lens, taking care to extend these findings to the beta- and alpha-crystallins where pertinent.

Automated summary

The nuclear region of the lens is metabolically quiescent, but far from inert chemically, with changes in the lens proteome, lipidome, and metabolome after decades of environmental exposures. Crystallins have mechanisms to resist chemical modifications and minimize light-scattering aggregation in the lens over a lifetime. Redox chemistry, mediated by Cys residues, plays a major role in these damages and adaptations, making it a key component of potential therapeutic strategies for preserving lens transparency during aging.