Crystallin sulfhydryl group (P-SH)

Sulfhydryl (SH) groups of soluble lens proteins, primarily the alpha, beta, and gamma crystallins, are critical structural components responsible for maintaining the transparency and refractive index of the eye lens. In a healthy lens, these thiol groups remain in a reduced state, supported by high concentrations of endogenous glutathione, which prevents the formation of aberrant protein linkages. As the lens ages or is exposed to oxidative stress, these sulfhydryl groups undergo oxidation to form inter-molecular disulfide bonds, leading to the formation of high-molecular-weight protein aggregates. These aggregates scatter light and cause the opacification characteristic of cataracts, the leading cause of blindness worldwide. Therapeutic targeting of these groups involves the use of antioxidant or 'anticataract' agents that either protect SH groups from oxidation or reduce existing disulfide bonds back to their soluble monomeric state. Drugs like bendazac lysine are intended to stabilize these proteins and prevent the progressive denaturation and aggregation that occurs during senile and diabetic cataract development.

Other names

Lens protein sulfhydryl groupsProtein-bound thiolsSoluble lens protein thiolsCrystallin thiols

Prevention of oxidative modification and disulfide cross-linking of protein thiols; stabilization of soluble crystallins; reduction of high-molecular-weight protein aggregates.