Production of biologically active N alpha-desacetylthymosin alpha 1 in Escherichia coli through expression of a chemically synthesized gene.
Wetzel. R R; Heyneker. H L HL; Goeddel. D V DV; Jhurani. P P; Shapiro. J J; Crea. R R; Low. T L TL; McClure. J E JE; Thurman. G B GB; Goldstein. A L AL
Key Findings
- A synthetic gene for thymosin‑alpha‑1 was inserted into E. coli and expressed as a fusion protein.
- The bacterial product lacks the N‑terminal acetyl group but has the same amino‑acid sequence as the natural peptide.
- Biological assays (MIF, TdT, RIA) confirmed the desacetyl peptide is as active as native thymosin‑alpha‑1.
Practical Outcomes
- This shows that recombinant, bacteria‑derived thymosin‑alpha‑1 (including the desacetyl form) can be biologically effective, suggesting alternative sourcing options for biohackers. However, the paper provides no dosing, safety, or human efficacy data, so any self‑experimentation should be approached cautiously.
Summary
Scientists engineered bacteria to make thymosin‑alpha‑1, a peptide that helps the immune system. The version they produced is missing a small acetyl group at the start, but tests show it works just like the natural hormone from animal thymus.
Abstract
Thymosin alpha 1, an immune restorative polypeptide hormone, was synthesized in Escherichia coli by using recombinant DNA cloning techniques. Based on the known amino acid sequence, a gene coding for the thymosin alpha 1 polypeptide chain was designed and enzymatically assembled from chemically synthesized oligodeoxyribonucleotide fragments. The gene was ligated into plasmid pBR322 and placed under lac operon control, and N alpha-desacetylthymosin alpha 1 was expressed as part of a beta-galactosidase chimeric protein. Cyanogen bromide cleavage of this protein gave a mixture of polypeptides, among which thymosin alpha 1 activity was detected by radioimmunoassay (RIA). The E. coli product is identical with native thymosin alpha 1 isolated from calf thymus in the amino acid sequence but lacks the N-terminal acetyl group. Results of a guinea pig migration inhibition factor (MIF) assay, a terminal deoxyribonucleotidyl transferase (TdT) assay, and radioimmunoassay indicate that the N alpha-desacetylthymosin alpha 1 produced by deoxyribonucleic acid (DNA) cloning techniques has biological activity equivalent to that of the native hormone.
Study Information
pubmed
1980
1980-12-23T00:00:00.000Z
10.1021/bi00567a023