Green tea flavanols protect human γB-crystallin from oxidative photodamage.

Age related cataract is a major cause of visual loss worldwide that is a result of opacification of the eye lens proteins. One of the major reasons behind this deterioration is UV induced oxidative damage. The study reported here is focused on an investigation of the oxidative stress induced damage to γB-crystallin under UV exposure. Human γB-crystallin has been expressed and purified from E. coli. We have found that epicatechin gallate (ECG) has a higher affinity towards the protein compared to epigallocatechin (EGC). The in vitro study of UV irradiation under oxidative damage to the protein in the presence of increasing concentrations of GTPs is indicative of their effective role as potent inhibitors of oxidative damage. Docking analyses show that the GTPs bind to the cleft between the domains of human γB-crystallin that may be associated with the protection of the protein from oxidative damage.