The identification of prothymosin a-like material in vertebrate lymphoid organs by a radioimmunoassay for the N-terminal decapeptide
Por:
Yialouris P.P., Evangelatos G.P., Soteriadis-Vlahos C., Heimer E.P., Felix A.M., Tsitsiloni O.E., Haritos A.A.
Publicada:
1 ene 1988
Resumen:
A radioimmunoassay (RIA) is described for the detection and quantitation of prothymosin a (ProT a), and its N-terminal fragments containing as a minimum the first ten amino acid residues. This range of peptides includes thymosins a1 (T a1) and a11 (T a11). Antibodies against T a1 and the tracera1(1-10)Tyr11(125I), an analogue of the major epitope, were utilized in this RIA. 50% displacement of the ligand was observed with 1.3 pmol of T a1 and 6.4 pmol of ProT a. The partially homologous parathymosin a (ParaT a) showed less than 2% crossreactivity with ProT A. Sephacryl S-200 gel filtration separation of the peptides of calf thymus, chicken spleen and trout spleen extracts prepared by a method eliminating proteolysis, combined with the above RIA, showed the presence of a major immunoreactive peak. Its elution volume corresponded to that of rat ProT a (apparent mol. weight 36000) for both calf (37000) and chicken (35000) tissues. In trout it corresponded to a significantly higher molecular weight (62000). No detectable levels of shorter fragments, including T a1, were observed in any of the above species. The levels of ProT a-like peptides in calf thymus, chicken spleen and trout spleen were found to be 246, 8.6 and 7.7 µg respectively, of rat ProT a equivalents per gram of fresh tissue. The significance of the presence of ProT a-like polypeptides in vertebrate species as distant as fish and mammals, the absence of short T a1-like fragments, and the relative conservation of the N-terminus as suggested by the RIA is discussed. © 1988.
Filiaciones:
Yialouris P.P.:
Zoological Laboratory, Faculty of Science, University of Athens, GR 157 84 Athens, Greece
Evangelatos G.P.:
Radioimmunochemistry Laboratory, National Research Center of Natural Sciences 'Demokritos', Aghia Paraskevi, GR 153 10 Athens, Greece
Soteriadis-Vlahos C.:
Radioimmunochemistry Laboratory, National Research Center of Natural Sciences 'Demokritos', Aghia Paraskevi, GR 153 10 Athens, Greece
Heimer E.P.:
Peptide Research Department, Roche Research Center, Hoffmann-La Roche Inc., Nutley, NJ 07110, United States
Felix A.M.:
Peptide Research Department, Roche Research Center, Hoffmann-La Roche Inc., Nutley, NJ 07110, United States
Tsitsiloni O.E.:
Zoological Laboratory, Faculty of Science, University of Athens, GR 157 84 Athens, Greece
Haritos A.A.:
Zoological Laboratory, Faculty of Science, University of Athens, GR 157 84 Athens, Greece
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