Characterization of a protein containing D-aspartic acid in aged mouse lens

A protein containing D-aspartic acid (D-Asp) was isolated from water insoluble (WI) fraction of naturally aged mice lens. The molecular weight of this protein was estimated to be about 10000 by gel permeation chromatography. High content of serine and glycine was noteworthy and the two amino acids occupy about 50 % of the total amino acids in the protein containing D-Asp.