IN-VITRO UV-B EFFECT ON LENS PROTEIN SOLUTIONS

To investigate the effects of UV-B exposure on the protein solutions o f different lens parts, rabbit lenses were separated into the equator (Eq), anterior cortex (Ac), nucleus (Nu) and posterior cortex (Pc). Af ter homogenization, the water-soluble protein from each part was irrad iated with UV-B at 0 to 0.225 J/cm(2). Alterations in the content of p rotein SH, carbonyl groups, light scattering intensity and SDS-PAGE pa ttern were measured to compare the effect of UV-B on the protein solut ions of various lens parts with or without additional GSH to test its preventive effect, The results showed that after UV-B irradiation, the protein sulfhydryl groups are gradually reduced. The nonprotein thiol (GSH added to the protein solution) was lost more rapidly than the pr otein sulfhydryl. The high molecular bands on the SDS-PAGE pattern mai nly aggregated with disulfide. UV-B damage also increased the content of carbonyl groups and light scattering, irrespective of the lens part s, Lens proteins from the equator suffered the least damage while thos e of the nucleus were most strongly affected by UV-B exposure. This st udy suggests that the lens proteins from various lens parts have diffe rent responses to UV-B exposure; the sensitivity was in the following order: Eq<Ac less than or equal to Pc<Nu.