title: The Ch21 protein, developmentally regulated in chick embryo, belongs to the superfamily of lipophilic molecule carrier proteins.
abstract: Ch21, a developmentally regulated low molecular weight protein observed in chick embryo skeletal tissues, is expressed "in vitro" by differentiating chondrocytes at a late stage of development. Here we report the complete amino acid sequence of the protein. 86% of the total amino acid sequence was deduced by sequences of 17 high performance liquid chromatography-separated proteolytic fragments and 33 amino acid residues at the amino-terminal end of protein purified from spent culture medium of hypertrophic chondrocytes. Furthermore we isolated by molecular cloning the corresponding cDNA and determined its nucleotide sequence. By combining protein and nucleotide sequence data we determined the primary structure of the entire Ch21. It consists of 158 amino acids and has a molecular mass of 18.065 kDa. Computer-assisted analysis showed that the Ch21 belongs to the superfamily of low molecular weight proteins sharing a basic framework for binding and transport of small hydrophobic molecules.
authors.affiliation: Laboratorio Differenziamento Cellulare, Istituto Nazionale per la Ricerca sul Cancro, Genova, Italy.
authors.forename: F D
authors.initials: FD
authors.lastname: Cancedda
authors.forename: B
authors.initials: B
authors.lastname: Dozin
authors.forename: F
authors.initials: F
authors.lastname: Rossi
authors.forename: F
authors.initials: F
authors.lastname: Molina
authors.forename: R
authors.initials: R
authors.lastname: Cancedda
authors.forename: A
authors.initials: A
authors.lastname: Negri
authors.forename: S
authors.initials: S
authors.lastname: Ronchi
mesh_terms: D000595:Amino Acid Sequence; D000818:Animals; D030161:Avian Proteins; D001483:Base Sequence; D002352:Carrier Proteins / Q000235:genetics*; D002642:Chick Embryo; D002851:Chromatography, High Pressure Liquid; D003001:Cloning, Molecular; D050556:Fatty Acid-Binding Proteins; D054834:Lipocalins; D008969:Molecular Sequence Data; D005810:Multigene Family; D010446:Peptide Fragments / Q000302:isolation & purification; D010957:Plasmids; D011487:Protein Conformation; D012689:Sequence Homology, Nucleic Acid
chemical_list: D030161:Avian Proteins; D002352:Carrier Proteins; C066299:Ch21 protein, chicken; D050556:Fatty Acid-Binding Proteins; D054834:Lipocalins; D010446:Peptide Fragments