title: The structure of a naturally occurring 10K polypeptide derived from the amino terminus of bovine thyroglobulin.
abstract: A combination of data derived from peptide sequencing and nucleic acid sequencing of cloned cDNA fragments has been used to define the complete amino acid sequence of a 10,000 M.W., thyroxine containing polypeptide derived from bovine thyroglobulin. This fragment, TG-F, which was obtained following reduction and alkylation, has been placed at the amino terminus of the parent protein with hormone located at residue 5 in the primary sequence of the thyroglobulin molecule. The carboxyl terminal sequence of this fragment -Cys-Gln-Leu-Gln is found on the N-terminal side of a lys residue, suggesting that the peptide bond cleavage which occurs to produce this 80 residue fragment from the parent (330K) thyroglobulin chain is a gln-lys. In addition, the amino acid sequence of this 10K fragment contains: No sequence which would be a substrate for glycosylation and no carbohydrate. Several repeated homologous amino acid sequences. A striking number of beta-bends predicted from Chou-Fasman analyses, particularly near its carboxyl terminus.
mesh_terms: D000595:Amino Acid Sequence; D000818:Animals; D002417:Cattle; D004247:DNA; D010446:Peptide Fragments / Q000235:genetics; D011487:Protein Conformation; D013954:Thyroglobulin / Q000235:genetics
chemical_list: D010446:Peptide Fragments; D004247:DNA; D013954:Thyroglobulin