title: Peptide mass fingerprinting of chaperonin-containing TCP-1 (CCT) and copurifying proteins.
abstract: The chaperonin-containing TCP-1 (CCT), found in the eukaryotic cytosol, is currently the focus of extensive research, CCT isolated from mouse testis lysate sediments at 20S in a sucrose gradient and accounts for about 70% of the total protein in this fraction. We intend to identify all the other proteins that copurify with CCT and to compile a reference profile for future studies. Their identification can be accelerated by a combination of protease digestion, matrix-assisted laser desorption-mass spectrometry, and database matching known as peptide mass fingerprinting. We applied this strategy to 32 polypeptides resolved by 2-dimensional gel electrophoresis, and 23 known proteins and 6 novel proteins were identified. We analyzed isoelectric variants of the CCT subunits and differences in the peptide mass spectra of two CCT theta isoforms indicated a novel posttranslational modification of this subunit.
authors.affiliation: CRC Centre for Cell and Molecular Biology, Institute of Cancer Research, Chester Beatty Laboratories, London, United Kingdom.
authors.forename: G
authors.initials: G
authors.lastname: Hynes
authors.forename: C W
authors.initials: CW
authors.lastname: Sutton
authors.forename: S
authors.initials: S
authors.lastname: U
authors.forename: K R
authors.initials: KR
authors.lastname: Willison
mesh_terms: D000595:Amino Acid Sequence; D000818:Animals; D056404:Chaperonin Containing TCP-1; D018833:Chaperonins / Q000737:chemistry*; D016208:Databases, Factual; D015180:Electrophoresis, Gel, Two-Dimensional; D014644:Genetic Variation; D007526:Isoelectric Point; D008297:Male; D051379:Mice; D018832:Molecular Chaperones / Q000737:chemistry; D008969:Molecular Sequence Data; D008970:Molecular Weight; D010449:Peptide Mapping / Q000379:methods*; D017510:Protein Folding; D011499:Protein Processing, Post-Translational; D019032:Spectrometry, Mass, Matrix-Assisted Laser Desorption-Ionization / Q000379:methods*; D013737:Testis / Q000737:chemistry*
chemical_list: D018832:Molecular Chaperones; C533315:Tcp1 protein, mouse; D056404:Chaperonin Containing TCP-1; D018833:Chaperonins