Age-related changes in human lens crystallins identified by two-dimensional electrophoresis and mass spectrometry

Exp Eye Res. 1998 Jul;67(1):31-43. doi: 10.1006/exer.1998.0481.


The purpose of this study was to identify the major protein components in adult human lenses and to analyse the specific age-related changes in these proteins using two-dimensional electrophoresis, Edman sequencing, and in conjunction with the data in the accompanying manuscript, mass spectrometry. The majority of changes in the two-dimensional electrophoretic pattern of lens proteins occurred prior to 17 years of age, and included a decrease in proteins migrating to the original positions of beta B1, beta B3, beta A3, gamma C and gamma D, and the appearance of many new species with apparent molecular weights on two-dimensional electrophoretic gels similar to beta B2 and gamma S, but having more acidic pIs. These proteins were identified as deamidated forms of beta B1 and beta A3/A1 missing portions of their N-terminal extensions. With the exception of alpha B, deamidation was detected in all crystallin species. These data indicated that a major fraction of the water-soluble protein of the adult human lens is composed of truncated beta B1 and beta A3/A1 crystallins, and that nearly all human crystallins, including the, beta-crystallins, are susceptible to deamidation. The results also provided the most detailed map to date of the identities of protein species on two-dimensional electrophoresis gels of adult human lenses.

Publication types

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

MeSH terms

  • Adolescent
  • Aging / metabolism*
  • Cataract / metabolism
  • Child, Preschool
  • Crystallins / chemistry*
  • Electrophoresis, Gel, Two-Dimensional
  • Humans
  • Infant
  • Lens, Crystalline / chemistry
  • Lens, Crystalline / embryology*
  • Mass Spectrometry
  • Middle Aged


  • Crystallins