Taxon-specific zeta-crystallin of camel eye lens: A comparative in silico studies

Abstract

The eye lens is a specialized organ of the visual system, which is transparent due to its complex geometry and unique protein composition. Nature has designed it to focus light on the retina throughout the life span. Several factors (post-translational modifications, thermal and solar radiations) causes aggregation of the lens proteins and result in early-onset of cataract. A cataract is one of the major causes of blindness worldwide. It's interesting how camel eyes maintain lens transparency in a harsh desert climate? The camel eye lenses contain a novel protein zeta (ζ)-crystallin in a bulk amount that is also present in two other animals (guinea pig and Japanese frog) but is adopted for milder habitats. The camel lens ζ-crystallin is a poorly characterized protein. This study has investigated the physicochemical and structural properties of camel, guinea pig, and Japanese frog’s ζ-crystallin. The docking results showed a strong affinity between NADPH and ζ-crystallin. RMSD, RMSF, radius of gyration, and SASA analysis in the ligand-free and bound states showed distinct prope6rties in these ζ-crystallins. Moreover, the hydrophobicity of camel and Japanese frog ζ-crystallin is lower than ζ-crystallin of other mammalian sources. The unique physicochemical and structural properties of taxon-specific ζ-crystallin are likely to maintain lens transparency.

Keywords

• Zeta-crystallin
• Structure modeling
• Eye lens proteins
• Camel
• Protein solubility