Sequence analysis of betaA3, betaB3, and betaA4 crystallins completes the identification of the major proteins in young human lens

J Biol Chem. 1997 Jan 24;272(4):2268-75. doi: 10.1074/jbc.272.4.2268.


A combination of Edman sequence analysis and mass spectrometry identified the major proteins of the young human lens as alphaA, alphaB, betaA1, betaA3, betaA4, betaB1, betaB2, betaB3, gammaS, gammaC, and gammaD-crystallins and mapped their positions on two-dimensional electrophoretic gels. The primary structures of human betaA1, betaA3, betaA4, and betaB3-crystallin subunits were predicted by determining cDNA sequences. Mass spectrometric analyses of each intact protein as well as the peptides from trypsin-digested proteins confirmed the predicted amino acid sequences and detected a partially degraded form of betaA3/A1 missing either 22 or 4 amino acid residues from its N-terminal extension. These studies were a prerequisite for future studies to determine how human lens proteins are altered during aging and cataract formation.

Publication types

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

MeSH terms

  • Amino Acid Sequence
  • Base Sequence
  • Crystallins / chemistry*
  • DNA, Complementary / chemistry
  • Electrophoresis, Gel, Two-Dimensional
  • Humans
  • Infant
  • Lens, Crystalline / chemistry*
  • Molecular Sequence Data
  • Spectrometry, Mass, Fast Atom Bombardment
  • beta-Crystallin A Chain
  • beta-Crystallin B Chain


  • CRYBA1 protein, human
  • CRYBA4 protein, human
  • CRYBB3 protein, human
  • Crystallins
  • DNA, Complementary
  • beta-Crystallin A Chain
  • beta-Crystallin B Chain

Associated data

  • GENBANK/U59057
  • GENBANK/U59058
  • GENBANK/U71216