Analysis of UVA-related alterations upon aging of eye lens proteins by mini two-dimensional polyacrylamide gel electrophoresis

This study is a first approach to identify UVA-related alterations in situ of bovine eye lens proteins from the water-soluble and urea-soluble fractions upon aging. The fractions were obtained from irradiated long-term organ culture lenses and analyzed by mini two-dimensional gel electrophoresis. This micropreparative method followed by computer analysis allows high resolution and separation of microgram quantities of proteins and to detect spots which arose as a consequence of irradiation. To facilitate the analysis we first separated the water-soluble fraction into the major crystallin classes by gel filtration. Moreover, we immunoblotted the gel of the urea-soluble fraction with a specific antibody against the intermediate filament protein vimentin. Upon irradiation of young and adult lenses, alphaA-crystallin and vimentin showed obvious modifications. During aging the susceptibility to irradiation increased when vimentin started to degrade, whereas deamidation of alphaA-crystallin seems to occur.