MicroELISA method for the determination of thymosin beta 9 discriminating between thymosin beta 9 and the structurally closely related thymosin beta 4.
Mihelić. M M; Kalbacher. H H; Hannappel. E E; Voelter. W W
Key Findings
- Antibodies made against the N‑terminal fragment (amino acids 1‑14) of thymosin beta‑9 show less than 1% cross‑reactivity with thymosin beta‑4.
- Antibodies raised against the native thymosin beta‑9 fragment cross‑react about 35% with thymosin beta‑4.
- Using N‑terminal fragments of similar peptides may be a general strategy to develop highly specific antibodies for distinguishing closely related peptides.
Practical Outcomes
- The main practical point is that accurate measurement of thymosin beta‑9 in tissues or blood requires these specially designed antibodies; standard tests may not differentiate it from beta‑4. For most self‑experimenters, this doesn’t change how you would take the peptide, but it warns that existing commercial assays might not be specific enough.
Summary
Scientists created a new lab test that can reliably tell the difference between two almost identical proteins, thymosin beta‑9 and thymosin beta‑4, by using a specific part of the beta‑9 protein to make antibodies. This is mainly a research tool and doesn’t give any new dosing or usage advice for people who take these peptides.
Abstract
In order to obtain specific antibodies against thymosin beta 9 showing minimal cross-reactivity with the highly homologous peptide thymosin beta 4, the N-terminal fragment 1-14 of thymosin beta 9 was used for immunization. These antibodies have been tested in a competitive ELISA and show less than 1% cross-reactivity with thymosin beta 4. On the other hand, antibodies raised against the native thymosin beta 9 (1-14) cross-react 35% with thymosin beta 4. Specific antibodies against thymosin beta 9 are important for studying the concentration and localization of thymosin beta 9 in thymus and other bovine tissues because thymosin beta 9 is always accompanied by thymosin beta 4. Using N-terminal fragments of thymosin beta 4-like peptides may be a general approach for obtaining specific antibodies since this part of sequence is less conserved in thymosin beta 4-like peptides.
Study Information
pubmed
1989
1989-08-15T00:00:00.000Z
10.1016/0022-1759(89)90328-1
16
12