Antisera to alpha crystallin as probes to study changes in lens proteins during human cataractogenesis

Antisera have been made to synthetic peptides that correspond to eight different regions of the alpha A molecule. Together with a solid phase radioimmunoassay, these antisera have been used to quantitatively assess binding to enriched alpha crystallin preparations from six different cataractous and six different normal lenses. Seven of the eight antisera show no difference in binding to alpha crystallin from cataractous versus normal lenses, whereas the antiserum directed against the alpha A sequence 120-130 shows a statistically significant decrease in binding to the alpha crystallin from cataractous lenses. Together, these studies demonstrate the feasibility of using antipeptide sera as probes of polypeptide changes during cataractogenesis and suggest that the region of the alpha A crystallin molecule encompassing residues 120-300 may undergo covalent and/or noncovalent structural modification during the process of opacification in the human senile lens.