Aspartic acid racemization in heavy molecular weight crystallins and water insoluble protein from normal human lenses and cataracts

Proc Natl Acad Sci U S A. 1978 Mar;75(3):1204-8. doi: 10.1073/pnas.75.3.1204.


High D/L aspartic acid ratios are observed in heavy molecular weight aggregates and in water-insoluble protein extracted from whole lenses and nuclear and cortical regions. Purified alpha-, beta-, and gamma-crystallins have low D/L ratios. Fractionation of urea-solubilized material from the water-insoluble protein yields four molecular weight classes of proteins. Fractions representing crosslinked material or apparently degraded products have high D/L ratios. Racemization within lens proteins may contribute to formation of the water-insoluble fraction seen in aging lenses and cataracts.

Publication types

  • Research Support, U.S. Gov't, P.H.S.

MeSH terms

  • Adolescent
  • Adult
  • Aged
  • Aging*
  • Aspartic Acid* / metabolism
  • Cataract / metabolism*
  • Child
  • Child, Preschool
  • Crystallins* / metabolism
  • Humans
  • Infant
  • Infant, Newborn
  • Lens, Crystalline / metabolism
  • Lens, Crystalline / ultrastructure
  • Middle Aged
  • Molecular Weight
  • Protein Conformation
  • Solubility
  • Stereoisomerism


  • Crystallins
  • Aspartic Acid