title: A radioimmunoassay for parathymosin alpha using antibodies to synthetic N-terminal peptide 1-30.
abstract: Antibodies against the N-terminus of rat parathymosin alpha have been raised in rabbits by conjugating parathymosin alpha (1-30) to hemocyanin. A radioimmunoassay for parathymosin alpha was established by utilizing antibodies against the above polypeptide and parathymosin alpha(1-12)[Tyr] as tracer. The useful range was 5-450 pmol for parathymosin alpha. An epitope was located in the amino acid sequence 1-12. The antiserum failed to crossreact with the same molar concentrations of the partly homologous thymosin alpha 1 or prothymosin alpha. With this radioimmunoassay, parathymosin alpha was isolated from calf thymus after separation from prothymosin alpha by reversed phase HPLC. Endogenous proteases did not appear to generate N-terminal fragments of parathymosin alpha in rat liver extracts in a similar fashion to that observed for prothymosin alpha. Parathymosin alpha has a ubiquitous distribution in the human tissues examined, with levels ranging from 93 (brain) to 1043 (liver) ng of parathymosin alpha(1-30) equivalents/g (wet weight).
mesh_terms: D000328:Adult; D000368:Aged; D000595:Amino Acid Sequence; D000818:Animals; D002417:Cattle; D002851:Chromatography, High Pressure Liquid; D003429:Cross Reactions; D005260:Female; D006801:Humans; D007106:Immune Sera / Q000032:analysis; D007223:Infant; D008969:Molecular Sequence Data; D010446:Peptide Fragments / Q000276:immunology*; D010447:Peptide Hydrolases; D011817:Rabbits; D011863:Radioimmunoassay / Q000379:methods; D013947:Thymosin / Q000031:analogs & derivatives* / Q000032:analysis / Q000276:immunology; D014018:Tissue Distribution
chemical_list: D007106:Immune Sera; D010446:Peptide Fragments; D013947:Thymosin; C044498:parathymosin alpha; D010447:Peptide Hydrolases