Population Character and Variety in Subunit Structure of High-Molecular-Weight Proteins from the Bovine Eye Lens.

1. High-molecular-weight fractions were isolated from extracts of the cortex and the nucleus of calf lenses. By chromatography of this material on large-pore agarose gels a separation into two populations, with S20,w-values ranging from 100 to 190 S and from 30 to 55 S was obtained. 2. It is shown that the high-molecular-weight fraction is identical to α-crystallin in poly-peptide chain composition. 3. For the α-crystallin fractions from the nucleus a subunit structure different from that of cortical α-crystallin fractions is found. 4. The quaternary structure of the α-crystallin fractions is not constant during the life span of the animal. The variety in subunit structure and state of aggregation of the α-crystallin molecule is supposed to be due to aging processes. [ABSTRACT FROM AUTHOR]