title: Structural studies on individual components of bovine transferrin.
abstract: The single-banding components of bovine transferrin from animals homozygous for the four transferrin variants found in the U.K. were isolated. Sedimentation equilibrium ultracentrifugation and sodium dodecyl sulphate-polyacrylamide-gel electrophoresis showed that the bands of a single variant have molecular weights of 77500 and 73300 respectively. The different bands of a single variant and single bands of different variants show no evidence of size heterogeneity or of low-molecular-weight peptides being split off after reduction in 6m-guanidine hydrochloride. The two slower bands of a single variant, which both contain 2 molecules of sialic acid/molecule of protein, have the same molecular weight and amino acid composition, and give identical peptide ;maps', although differences in composition and peptide ;maps' occur between the different variants. The results support the concept that bovine transferrin is essentially a single polypeptide chain, but they do not explain differences in electrophoretic mobility between bands of the same variant which are not produced by differing sialic acid content.
mesh_terms: D000596:Amino Acids / Q000032:analysis; D000818:Animals; D002417:Cattle; D004591:Electrophoresis, Polyacrylamide Gel; D007122:Immunoelectrophoresis; D008970:Molecular Weight; D009438:Neuraminic Acids / Q000032:analysis; D010455:Peptides / Q000032:analysis; D011487:Protein Conformation; D014168:Transferrin / Q000032:analysis*; D014461:Ultracentrifugation
chemical_list: D000596:Amino Acids; D009438:Neuraminic Acids; D010455:Peptides; D014168:Transferrin