Figure 3. Pb alters α-crystallin processing in cultured lenses. A: Two dimensional gels of HPLC purified α-crystallin from cultured lenses (3 days; 1 uM Pb(NO₃)₂). B: Quantification of the relative amounts of various post-translationally modified forms of α-crystallin in cultured lenses (3 days; 1 uM Pb(NO₃)₂). Spot densities (normalized to either dominant αA- or αB-crystallin protein spot) of different isoforms of α-crystallin are altered with Pb-exposure (3 days; 1 uM Pb(NO₃)₂). Only protein spots sufficiently resolved from neighboring protein spots were quantified. C: α-Crystallin purified from lenses exposed in vitro to Pb (3 days; 1 uM Pb(NO₃)₂) does not exhibit alterations in chaperone function. Dash/dot line (- - -) shows aggregation of denatured lactalbumin without α-crystallin. Solid line (—) shows aggregation of denatured lactalbumin in the presence of α-crystallin purified from lenses cultured in control media. Unconnected circles (o o o) show aggregation of denatured lactalbumin in the presence of α-crystallin purified from lenses cultured in the presence of Pb.