Identification of phosphorylation and acetylation sites in alphaA-crystallin of the eye lens ( mus musculus) after two-dimensional gel electrophoresis.
Posttranslational modifications are of great interest because of their relevance in biological systems as proteins are commonly activated or deactivated by phosphorylation, glycation and acetylation [1, 2]. During eye lens aging the number of the alphaA-crystallin isoproteins increases. This could be observed by the use of 2D-PAGE (two-dimensional gel electrophoresis). The number of alphaA-crystallin spots in the gel increased during eye lens aging. For further analysis the spots of 2D-PAGE were cut out and the identification of the proteins was done using nanoLC-ESI-MS/MS (liquid chromatography electrospray ionization tandem mass spectrometry). The created MS/MS-data were analyzed using the Sequest algorithm. Searches with different parameters were done to preferably get the complete sequence coverage and to identify posttranslational modifications of the alphaA-crystallin. The acetylated N-terminus of this protein could be detected. Furthermore, phosphorylation of serine 122 and 148 was identified in two different spots.
Schaefer
Heike
H
Medical Proteom-Center, Ruhr-University of Bochum, Bldg. ZKF E.141, Universitätsstrasse 150, 44801 Bochum, Germany.
Marcus
Katrin
K
Sickmann
Albert
A
Herrmann
Marion
M
Klose
Joachim
J
Meyer
Helmut E
HE
D000107:Acetylation; D000595:Amino Acid Sequence; D000818:Animals; D015180:Electrophoresis, Gel, Two-Dimensional / Q000379:methods; D007908:Lens, Crystalline / Q000737:chemistry*; D051379:Mice; D008969:Molecular Sequence Data; D010446:Peptide Fragments / Q000737:chemistry; D010455:Peptides / Q000737:chemistry; D010766:Phosphorylation; D011499:Protein Processing, Post-Translational; D011506:Proteins / Q000737:chemistry; D012694:Serine / Q000737:chemistry; D019032:Spectrometry, Mass, Matrix-Assisted Laser Desorption-Ionization / Q000379:methods; D014357:Trypsin; D038202:alpha-Crystallin A Chain / Q000737:chemistry*
D010446:Peptide Fragments; D010455:Peptides; D011506:Proteins; D038202:alpha-Crystallin A Chain; D012694:Serine; D014357:Trypsin