Short regulatory and thymic peptides
Thymulin
Thymulin is a nine-residue peptide, pGlu-Ala-Lys-Ser-Gln-Gly-Gly-Ser-Asn, produced by thymic epithelial cells. Its biological activity depends on binding zinc.
- TypePeptide
- FormulaC33H54N12O15
- Average mass858.85 g/mol
- CAS78922-62-0
- Vesta listings1
Reference page for laboratory use · updated 2026-10-30
Overview
Thymulin at a glance
Thymulin was first described as facteur thymique sérique (FTS), a circulating thymic factor, and the literature calls it a zinc-dependent hormone. Only the zinc-bound form is active in the classical assays, which is why papers discuss the peptide and its zinc complex separately.
The peptide has an N-terminal pyroglutamic acid and a free C-terminus. The identity numbers on this page describe the peptide on its own. The zinc-bound form is heavier by roughly one zinc atom (about 65 Da) less any protons it displaces, and its spectra show the isotope pattern of zinc.
Vesta lists one product under the combined name Thymalin/Thymulin. The batch documents should say whether the vial contains the defined peptide described here or the Thymalin peptide fraction described on its own page.
Structure
The sequence is pyroglutamyl-alanyl-lysyl-seryl-glutaminyl-glycyl-glycyl-seryl-asparagine. The N-terminal residue is cyclised pyroglutamic acid, which has no free amine, and zinc binds to the peptide in a 1:1 ratio.
Identity
Identity data
| Name | Thymulin |
|---|---|
| Also written as | Facteur thymique sérique, FTS, Zinc thymulin |
| Type | Peptide |
| Research area | Short regulatory and thymic peptides |
| Molecular formula | C33H54N12O15 |
| Monoisotopic mass | 858.3832 Da |
| Average molecular weight | 858.85 g/mol |
| CAS number | 78922-62-0 |
| Sequence | pGlu-Ala-Lys-Ser-Gln-Gly-Gly-Ser-Asn |
| PubChem record | CID 71300623 |
The formula was calculated independently from the written sequence and matches the PubChem record exactly. Reference data retrieved on 2026-10-30. Compare these values with the batch certificate of analysis, using the compound identity file template.
Expected values
Mass spectrometry reference
Ions calculated from the monoisotopic mass 858.3832 Da. Use them to check an LC-MS result; for larger peptides the instrument usually reports a deconvoluted mass close to 858.9 Da instead.
| Ion | m/z |
|---|---|
| [M+H]+ | 859.3905 |
| [M+2H]2+ | 430.1989 |
| [M+Na]+ | 881.3724 |
| [M+K]+ | 897.3464 |
Read the guide to average and monoisotopic mass for how these values are calculated.
Quality
Analytical notes for batch documents
- Zinc has five stable isotopes (64Zn, 66Zn, 67Zn, 68Zn and 70Zn), so a zinc-containing species shows a wide isotope pattern. The peptide without zinc shows an ordinary pattern.
- Ask whether the batch is the zinc complex or the peptide alone, and for the zinc content if it is the complex. The molecular weight on a certificate depends on the answer.
- Asn and Gln can deamidate (+0.984 Da). A shoulder or a small peak at that mass difference is a common finding in an older sample.
- The pyroglutamate N-terminus can form from glutamine during synthesis or storage. If a batch is supposed to start with pyroglutamate, an ion 17.027 Da heavier points to unconverted glutamine.
- Mass shifts to look for in this sequence: deamidation of Asn or Gln (+0.984 Da).
- The molecular weight of a vial of powder includes counter-ions and water; the share of the powder that is peptide is the net peptide content.
Terms used on this page: Peptide, C-terminus, Pyroglutamate, N-terminus.
Vesta listings
Thymulin formats and prices
| Product | Per vial | SKU | Price per kit | Price per vial |
|---|---|---|---|---|
| Thymalin/Thymulin | 10 mg | TY10 | $108.21 | $10.82 |
Vesta lists one product called Thymalin/Thymulin. Confirm from the batch documents which of the two it contains.
Prices are per kit of 10 vials in US dollars. Shipping is paid by the customer and is shown in the cart. Volume savings of 5 %, 8 % and 10 % apply from $350.00, $600.00 and $1,000.00. See the full price list.
Published literature
Selected scientific literature
Bibliographic details were read from PubMed on 2026-10-30. The papers are listed for scientific reference; Vesta makes no claim about the use of its research materials in people or animals.
- Thymulin, a zinc-dependent hormoneBach JF, Dardenne M · Med Oncol Tumor Pharmacother · 1989 · PMID 2657247
- Biochemical and biological aspects of the interaction between thymulin and zincDardenne M, Pléau JM, Savino W et al. · Prog Clin Biol Res · 1993 · PMID 7681212
- ThymulinPleau JM, Gastinel LN, Bach JF et al. · Methods Enzymol · 1985 · PMID 3878920
Questions
Frequently asked questions
What is Thymulin?
Thymulin is a nine-residue peptide, pGlu-Ala-Lys-Ser-Gln-Gly-Gly-Ser-Asn, produced by thymic epithelial cells. Its biological activity depends on binding zinc.
What is the molecular weight of Thymulin?
Thymulin has the formula C33H54N12O15, an average molecular weight of 858.85 g/mol and a monoisotopic mass of 858.3832 Da. A salt form, a different counter-ion or a metal complex changes the molecular weight printed on a certificate of analysis, so compare like with like.
How can I check the identity of a batch of Thymulin?
Compare the intact mass measured by LC-MS with the expected values on this page, for example [M+2H]2+ at m/z 430.1989. Confirm that one main HPLC peak carries that mass and that the batch code on the report matches the vial. The guides on mass spectrometry and on certificates of analysis explain each step.
Which Thymulin products does Vesta list?
Vesta lists 1 product for Thymulin: 10 mg per vial in kits of 10 vials. Prices are shown per kit in US dollars, and shipping is paid by the customer.
What is thymulin?
Thymulin is a nonapeptide, pGlu-Ala-Lys-Ser-Gln-Gly-Gly-Ser-Asn, produced by thymic epithelial cells. It was first called facteur thymique sérique (FTS), and its activity depends on binding zinc.
Is thymulin the same as Thymalin?
No. Thymulin is a single defined peptide. Thymalin is a mixture of short peptides extracted from thymus. Vesta lists one product called Thymalin/Thymulin, so check the batch documents.
Why does the molecular weight of thymulin depend on zinc?
The peptide alone is C33H54N12O15, 858.85 g/mol. The active complex binds one zinc atom, which adds up to about 65 g/mol (one zinc atom, less any protons it displaces), so a certificate must state which form it reports.