Post-translational modification of alphaB-crystallin of normal human lens.
The current study reports several post-translational modifications of alphaB-crystallin in normal human lenses. The isoforms of post-translational modified alphaB-crystallin were isolated from the normal human lenses of >70-age group by ion exchange chromatography and sodium dodecyl sulfate-polyacrylamide gel electrophoresis. The isoform modifications were determined in detail by fast atom bombardment mass spectroscopy and amino acid sequence analysis. As the criterion of non-modified alphaB-crystallin, alphaB-crystallin from 1-d-old infant lenses were used. The modifications found in this study involve oxidation of the N-terminal methionine-1 residue, phosphorylation of the serine-59 residue, and truncation of four amino acids from the C-terminal position of the crystallin. The oxidation of methionine-1 was found in the early stage of human life in 1-d-old lens, although other modification of alphaB-crystallin were usually only found in old lenses (>70-age group).
Kamei
A
A
Department of Biochemistry, Faculty of Pharmaceutical Sciences, Meijo University, Nagoya, Japan.
Hamaguchi
T
T
Matsuura
N
N
Iwase
H
H
Masuda
K
K
D000595:Amino Acid Sequence; D003459:Crystallins / Q000096:biosynthesis* / Q000737:chemistry / Q000235:genetics; D004591:Electrophoresis, Polyacrylamide Gel; D006801:Humans; D006868:Hydrolysis; D015151:Immunoblotting; D007908:Lens, Crystalline / Q000737:chemistry*; D008969:Molecular Sequence Data; D010084:Oxidation-Reduction; D010766:Phosphorylation; D011499:Protein Processing, Post-Translational / Q000235:genetics*; D016339:Spectrometry, Mass, Fast Atom Bombardment; D014357:Trypsin
D003459:Crystallins; D014357:Trypsin