Identification of the major components of the high molecular weight crystallins from old human lenses.

High molecular weight aggregates from the water soluble portion of four lenses from older donors were examined by mass spectrometric techniques that permitted unambiguous identification of the principal components as alpha A-, alpha B- and gamma s-crystallins. Post-translational modifications that were located and identified included deamidations in alpha A and gamma s and an intramolecular disulfide bond in alpha A-crystallin. The C-terminus of alpha A was not found, supporting previous suggestions that this portion of the protein may be important in preventing aggregation.

[1]  L. Takemoto,et al.  Presence of low molecular weight polypeptides in human brunescent cataracts. , 1983, Biochemical and biophysical research communications.

[2]  B. Ortwerth,et al.  Studies on the nature of the water-insoluble fraction from aged bovine lenses. , 1989, Experimental eye research.

[3]  A. Spector,et al.  High molecular weight protein from human lenses. , 1976, Experimental eye research.

[4]  O. Srivastava.  Age-related increase in concentration and aggregation of degraded polypeptides in human lenses. , 1988, Experimental eye research.

[5]  Y. Sun,et al.  Post-translational modifications of water-soluble human lens crystallins from young adults. , 1994, The Journal of biological chemistry.

[6]  T. Hunkapiller,et al.  Peptide mass maps: a highly informative approach to protein identification. , 1993, Analytical biochemistry.

[7]  G. Benedek,et al.  On the presence and mechanism of formation of heavy molecular weight aggregates in human normal and cataractous lenses. , 1973, Experimental eye research.

[8]  C. G. Edmonds,et al.  Mass spectrometric analysis of the structure of γII bovine lens crystallin , 1992 .

[9]  L. Takemoto,et al.  The C-terminal region of alpha-crystallin: involvement in protection against heat-induced denaturation. , 1993, The Biochemical journal.

[10]  L. Takemoto,et al.  Covalent change in alpha crystallin during human senile cataractogenesis. , 1988, Biochemical and biophysical research communications.

[11]  Jean B. Smith,et al.  Amino acid sequence of human lens βB2‐crystallin , 1993 .

[12]  U. K. Laemmli,et al.  Cleavage of Structural Proteins during the Assembly of the Head of Bacteriophage T4 , 1970, Nature.

[13]  A. Spector,et al.  Human alpha-crystallin: characterization of the protein isolated from the periphery of cataractous lenses. , 1976, Biochemistry.

[14]  G. Benedek,et al.  The concentration and localization of heavy molecular weight aggregates in aging normal and cataractous human lenses. , 1975, Experimental eye research.

[15]  L. Takemoto,et al.  Truncation of alpha A-crystallin from the human lens. , 1991, Experimental eye research.