Variations in the soluble alpha-crystallin proteins from human cataractous lenses.

Human cataractous lenses from subjects aged 20-91 years were extracted in tris/glycine buffer and fractionated on Sephadex G-75 column. Four fractions, F1, F2, F3 and F4 identified as alpha-, beta1-, beta2- and gamma-crystallin were obtained. Gel electrophoresis of alpha-crystallin in polyacrylamide containing 6M urea revealed changes in polypeptide composition, colouration; variation in band pattern and mean mobility. The relative mobilities of the protein bands were used to calculate coefficient of similarity within the same age group and among different age groups.