Racemization of aspartyl residues in proteins from normal and cataractous human lenses: an aging process without involvement in cataract formation.

A highly sensitive method was used to determine D- and L-aspartyl residues in protein fractions from normal and cataractous human lenses. A linear relationship with age was found in all fractions from normal lenses. However, no correlation with cataract could be established. It is concluded that racemization of aspartyl residues is a continuous process in eye-lens proteins but plays no role in cataract formation.