Abstract
When translated in the wheat germ system, mRNA from fresh calf thymus stimulates incorporation of radioactive amino acids into an acid-insoluble product, and 10--20% of the total radioactivity incorporated is precipitated with antisera to active thymosin fractions. In sodium dodecyl sulfate disc gel electrophoresis, radioactivity was recovered mainly in two peptides, corresponding to 16,000 and 11,000 daltons; the latter probably represents incomplete chains. Tryptic digests of each of these peptides yielded fragments corresponding to the sequence of residues 15--19 of thymosin alpha1; these peptides were characterized by cochromatography with digests of synthetic thymosin alpha1 and by Edman degradation. Thus, the 16,000-dalton peptide synthesized in the cell-free system appears to be q precursor of thymosin alpha1 and possibly of other peptides in the fractions isolated from calf thymus. The results support the conclusion that this peptide is synthesized in the thymus gland.
Full text
PDF




Selected References
These references are in PubMed. This may not be the complete list of references from this article.
- Böhlen P., Stein S., Stone J., Udenfriend S. Automatic Monitoring of primary amines in preparative column effluents with fluorescamine. Anal Biochem. 1975 Aug;67(2):438–445. doi: 10.1016/0003-2697(75)90316-4. [DOI] [PubMed] [Google Scholar]
- Goldstein A. L., Guha A., Zatz M. M., Hardy M. A., White A. Purification and biological activity of thymosin, a hormone of the thymus gland. Proc Natl Acad Sci U S A. 1972 Jul;69(7):1800–1803. doi: 10.1073/pnas.69.7.1800. [DOI] [PMC free article] [PubMed] [Google Scholar]
- Goldstein A. L., Low T. L., McAdoo M., McClure J., Thurman G. B., Rossio J., Lai C. Y., Chang D., Wang S. S., Harvey C. Thymosin alpha1: isolation and sequence analysis of an immunologically active thymic polypeptide. Proc Natl Acad Sci U S A. 1977 Feb;74(2):725–729. doi: 10.1073/pnas.74.2.725. [DOI] [PMC free article] [PubMed] [Google Scholar]
- Goldstein A. L., Rossio J. L. Thymosin for immunodeficiency diseases and cancer. Compr Ther. 1978 Feb;4(2):49–57. [PubMed] [Google Scholar]
- Goldstein A. L., Thurman G. B., Low T. L., Rossio J. L., Trivers G. E. Hormonal influences on the reticuloendothelial system: current status of the role of thymosin in the regulation and modulation of immunity. J Reticuloendothel Soc. 1978 Apr;23(4):253–266. [PubMed] [Google Scholar]
- Green M., Zehavi-Willner T., Graves P. N., McInnes J., Pestka S. Isolation and cell-free translation of immunoglobulin messenger RNA. Arch Biochem Biophys. 1976 Jan;172(1):74–89. doi: 10.1016/0003-9861(76)90049-7. [DOI] [PubMed] [Google Scholar]
- Roberts B. E., Paterson B. M. Efficient translation of tobacco mosaic virus RNA and rabbit globin 9S RNA in a cell-free system from commercial wheat germ. Proc Natl Acad Sci U S A. 1973 Aug;70(8):2330–2334. doi: 10.1073/pnas.70.8.2330. [DOI] [PMC free article] [PubMed] [Google Scholar]
- Tarr G. E. Improved manual sequencing methods. Methods Enzymol. 1977;47:335–357. doi: 10.1016/0076-6879(77)47036-8. [DOI] [PubMed] [Google Scholar]
- Weber K., Osborn M. The reliability of molecular weight determinations by dodecyl sulfate-polyacrylamide gel electrophoresis. J Biol Chem. 1969 Aug 25;244(16):4406–4412. [PubMed] [Google Scholar]
- Weber L. A., Hickey E. D., Maroney P. A., Baglioni C. Inhibition of protein synthesis by Cl-. J Biol Chem. 1977 Jun 10;252(11):4007–4010. [PubMed] [Google Scholar]