Partial characterization of three distinct populations of human γ-crystallins

Certain low molecular weight crystallins may be involved preferentially in the process of human cataractogenesis. Three distinct populations of monomeric crystallins with molecular weights ranging from 19,000 to 24,000 have been demonstrated previously by electrophoresis in the presence of sodium dodecyl sulfate (SDS). The authors now report the chromatographic separation of these three components from young human lenses. Each of the three species has unique profiles on isoelectric focusing and native polyacrylamide gels as well as on SDS gels. All three species show similar patterns of age-related modification in their charge characteristics. These three populations of polypeptides all appear to be γ-crystallins. The relative amounts of the three vary with age, which accounts for the greater ease of their separation in extracts from young lenses as compared with adult lenses.