Immunochemical characterization of the major low molecular weight polypeptide (10K) from human cataractous lenses.

Polyclonal antisera to whole crystallins and to synthetic peptides corresponding to various sequences of these crystallins have been used to probe Western blots that contain a low molecular weight component of approximately 10,000 daltons found in the water-soluble fractions from human cataractous lenses. This 10K component binds only to antiserum made against human gamma crystallin. Incubation of human cataractous lens homogenates with alpha chymotrypsin or trypsin will produce low molecular components of similar molecular weight, and identical specificity of binding to the gamma crystallin antiserum. Together, these results suggest that the gamma crystallins constitute a class of macromolecules that are susceptible to in vivo proteolysis during cataractogenesis of the aged human lens.