Protective effects of carnosine on dehydroascorbate-induced structural alteration and opacity of lens crystallins: important implications of carnosine pleiotropic functions to combat cataractogenesis.

The high level of dehydroascorbic acid (DHA) in the lenticular tissue is an important risk factor for the development of age-related cataracts. In this study, the effects of DHA on structure and function of lens crystallins were studied in the presence of carnosine using gel mobility shift assay, different spectroscopic techniques, and lens culture analysis. The DHA-induced unfolding and aggregation of lens proteins were largely prevented by this endogenous dipeptide.

The Structural Alteration and Aggregation of Bovine Lens Gamma-Crystallin by Homocysteinylation; The Pathomechanism Underlying Cataract Development During Hyperhomocysteinimia.

A significant association between increased level of blood homocysteine (hyperhomocysteinimia) and various eye pathological disorders including cataract has been reported. This metabolic byproduct is converted into a highly reactive cyclic thioester compound, homocysteine thiolactone (HCTL), which can potentially react with free amino groups in protein. In the current study, as bovine lens γ-Crystallin (γ-Cry) was incubated with HCTL, various spectroscopic techniques, gel mobility shift assay, and microscopic analysis were applied to characterize structural variation and aggregation of this protein.

Assessment of structure, stability and aggregation of soluble lens proteins and alpha-crystallin upon non-enzymatic glycation: The pathomechanisms underlying cataract development in diabetic patients.

Total soluble lens proteins (TSPs) and α-crystallin (α-Cry) were individually subjected to the long-term glycation in the presence of d-glucose. The glycated and non-glycated protein counterparts were incubated under different stress conditions and compared according to their structure, stability and aggregation propensity by various spectroscopic techniques and gel mobility shift analyses. Extensive glycation of the lens proteins was accompanied with structural alteration, reduction in their surface hydrophobicity and increment of their surface tension.