Concentration dependence of transmission losses in UV-laser irradiated bovine alpha-, beta H-, beta L- and gamma-crystallin solutions.

Experiments with calf lens protein fractions in aqueous buffer solutions at room temperature showed that beta H-, beta L- and gamma-crystallin fractions became opaque following ultraviolet exposure at 308 nm, while the alpha-crystallin fraction remained transparent. Transmission loss, due to UV-irradiation, for all of the crystallin samples was studied in the concentration range of 0.1 mg/mL to 1.0 mg/mL, and for alpha- and gamma-crystallin, in the range up to 5 mg/mL. With increased concentrations of beta H-, beta L- and gamma-crystallin, the rate of opacification increased. However, with alpha-crystallin, the loss of transmission was negligible for all of the concentrations and irradiation times studied. Opacification of the crystallins was accompanied by formation of higher molecular weight insoluble proteins as detected by SDS-PAGE.