Catalogue / Thymosin alpha-1
Thymosin alpha-1
Also written as Thymalfasin, Ta1.
A 28 residue N-terminally acetylated peptide with an unusually acidic sequence, which changes both how it behaves on a column and how it ionises.
| Molecular formula | C129H215N33O55 |
| Average mass | 3108.28 Da |
| Monoisotopic mass | 3106.5041 Da |
| Residues | 28 |
| Termini | N-terminal acetyl, C-terminal free acid |
| Class | Repair and regenerative peptides |
| Determination | Peptide analysis, specialist compound |
| Price | 590 USD |
Computed at build time from the composition shown on this page, not transcribed from a supplier datasheet.
Thymosin alpha-1 has an average molecular weight of 3108.28 daltons and a monoisotopic mass of 3106.5041 daltons. Identity is confirmed by matching the measured deconvoluted mass to that figure, and purity is reported separately by reversed-phase chromatography at 214 nm. The two numbers answer different questions and neither substitutes for the other.
| One letter | SDAAVDTSSEITTKDLKEKKEVVEEAEN |
| Three letter | Ser-Asp-Ala-Ala-Val-Asp-Thr-Ser-Ser-Glu-Ile-Thr-Thr-Lys-Asp-Leu-Lys-Glu-Lys-Lys-Glu-Val-Val-Glu-Glu-Ala-Glu-Asn |
| Modifications | N-terminal acetyl, C-terminal free acid |
The formula and both masses in the table above are derived from this sequence and these terminal modifications. A reader who believes a figure is wrong can check the composition rather than take the number on trust, which is the point of publishing it this way.
A sequence is not an identity result. It is the expected composition against which a measured mass is compared, and the comparison is what appears on the certificate.
| Charge | m/z |
|---|---|
| [M+3H]3+ | 1036.509 |
| [M+4H]4+ | 777.633 |
| [M+5H]5+ | 622.308 |
These are the ions an electrospray source is expected to produce for a neutral mass of 3106.5041 daltons, computed from the monoisotopic mass and the proton mass. They are what a raw spectrum should show before deconvolution.
A report that gives only a deconvoluted mass without the charge states it was derived from cannot be checked. Deconvolution is a calculation, and a calculation whose inputs are not shown is an assertion.
| The sequence carries nine acidic residues and ionises poorly in positive mode. Negative mode or a higher charge state is often required, and a laboratory reporting a weak positive-mode spectrum has not solved the problem. |
| Deamidation of asparagine and glutamine adds one dalton per site. On a 28 residue peptide this needs mass accuracy better than a unit, otherwise a degraded batch reads as intact. |
| Loss of the N-terminal acetyl group gives a 42 dalton lighter species that co-elutes closely. |
Every compound fails in its own way. A generic peptide method applied without regard to these specifics produces a number that looks like a result and is not one.
Fragment peptides derived from larger endogenous proteins. Because they are fragments, a supplier can ship a shorter truncation that still looks correct on a chromatogram.
LC-MS identity with deconvolution, purity by RP-HPLC at 214 nm, and net peptide content where the delivered milligram figure matters.
Where the delivered milligram figure matters rather than the percentage, net peptide content by combustion analysis and water by Karl Fischer are added, and the certificate carries a closed mass balance instead of a single purity number.
| LC-MS identity | Measured mass |
| RP-HPLC purity | Area at 214 nm |
| Net peptide content | Milligrams |
| Water content | Karl Fischer |
| Counter-ion | Ion chromatography |
| Bacterial endotoxins | USP <85> |
What is the molecular weight of Thymosin alpha-1?
The average molecular weight is 3108.28 daltons and the monoisotopic mass is 3106.5041 daltons, computed from the sequence SDAAVDTSSEITTKDLKEKKEVVEEAEN shown on this page. Both figures are calculated rather than transcribed, so they can be checked against the stated composition.
How is Thymosin alpha-1 tested for purity and identity?
LC-MS identity with deconvolution, purity by RP-HPLC at 214 nm, and net peptide content where the delivered milligram figure matters. Purity describes the chromatographable fraction only and is not the same quantity as the peptide mass delivered per vial.
What goes wrong when Thymosin alpha-1 is analysed?
The sequence carries nine acidic residues and ionises poorly in positive mode. Negative mode or a higher charge state is often required, and a laboratory reporting a weak positive-mode spectrum has not solved the problem.
What does Thymosin alpha-1 analysis cost at ANALYTON?
Peptide analysis, specialist compound is priced at 590 US dollars, covering the determinations described on this page. Content, safety and elemental determinations are ordered alongside and are priced separately on the price list.
Updated 2026-09-01. Masses computed at build, not transcribed.