title: Characterization of the chicken telokin heterogeneity by time-of-flight mass spectrometry.
abstract: Chicken gizzard telokin was purified to apparent homogeneity by sodium dodecyl sulfate-polyacrylamide gel electrophoresis. This preparation yielded upon mass spectrometry analysis seven mass peaks spanning from 15 858 to 17 100 Da. Anion exchange-high performance liquid chromatography of the purified telokin revealed a high diversity of telokin molecules. By combining protein chemistry to chromatography and mass spectrometry, the telokin heterogeneity was analyzed. Three acetylated N-termini were found, AMI, MIS, and SGR. Cyanogen bromide cleavage of telokin yielded six different C-terminal peptides corresponding to the removal of one to six C-terminal glutamyl residues from the protein sequence deduced from the cDNA. Phosphorylation of telokin was detected, thus increasing the heterogeneity of the telokin preparation. In addition, peptide sequencing has shown that telokin contained either an aspartyl or a glutamyl residue at position 27, probably resulting from chicken polymorphism.
authors.affiliation: Centre National de la Recherche Scientifique Unité de Recherche Associée 2054, Ecole Supérieure de Physique et de Chimie Industrielles de la Ville de Paris, Paris, France. rusconi@atlas.bio.espci.fr
authors.forename: F
authors.initials: F
authors.lastname: Rusconi
authors.forename: M C
authors.initials: MC
authors.lastname: Potier
authors.forename: J P
authors.initials: JP
authors.lastname: Le Caer
authors.forename: J M
authors.initials: JM
authors.lastname: Schmitter
authors.forename: J
authors.initials: J
authors.lastname: Rossier
mesh_terms: D000595:Amino Acid Sequence; D000818:Animals; D002645:Chickens; D002851:Chromatography, High Pressure Liquid; D013058:Mass Spectrometry; D008969:Molecular Sequence Data; D009124:Muscle Proteins / Q000737:chemistry*; D009219:Myosin-Light-Chain Kinase; D010446:Peptide Fragments; D010455:Peptides
chemical_list: D009124:Muscle Proteins; D010446:Peptide Fragments; D010455:Peptides; C060640:telokin; D009219:Myosin-Light-Chain Kinase