TB-500
TB-500 is the full-length 43-residue thymosin β4 protein (INN Timbetasin), supplied as a lyophilized research material.
Identity & structure
Verified identifiers, sequence, and analytical properties — every value machine-readable and independently sourceable against PubChem.
Primary sequence · 43 residues · N-terminal Acetyl.
| Identity | |
|---|---|
| CAS | 77591-33-4 |
| PubChem CID | 16132341 |
| FDA UNII | 549LM7U24W |
| Also known as | TB 500, TB500, TB 500 peptide, Timbetasin, Thymosin beta-4, Thymosin beta 4, Tbeta4, TB4, Fx Peptide |
| Research class | Regenerative & Cytoprotective |
| Structure | |
| Molecular formula | C212H350N56O78S |
| InChIKey | UGPMCIBIHRSCBV-XNBOLLIBSA-N |
| Sequence | Full-length thymosin β4 (43 residues) |
| Length | 43 residues |
| Analytical | |
| Average molecular weight | 4963.51 g/mol |
| Monoisotopic mass | 4960.4863 Da |
| Form | Lyophilized powder |
| Solubility | Water-soluble |
| Storage | 2–8 °C, desiccated |
Where TB-500 sits in its class
Molecular weight (g/mol) across the 15 characterized compounds in Regenerative & Cytoprotective. Compare all compounds →
Research context
TB-500 is the full-length 43-residue thymosin β4 protein (INN Timbetasin), supplied as a lyophilized research material. Its molecular formula is C212H350N56O78S, giving a molecular weight of 4963.51 g/mol. It is referenced in tissue and cytoskeletal research and is characterized by reversed-phase HPLC and mass spectrometry.
Not to be confused with: TB-500 Fragment (Ac-LKKTETQ) — A short actin-binding fragment sometimes marketed as "TB-500". The compound Lineará stocks under that name is full-length thymosin β4; this 7-residue fragment is listed here for characterization and disambiguation only.
Supplied solely as a characterized research material. No representation is made as to any biological effect. For Research Use Only — not for human or veterinary use.
How TB-500 is identified
Identity and purity are measured, not asserted. Electrospray mass spectrometry (ESI-MS) determines the mass-to-charge ratio of the intact molecule — an observed value matching the expected series above confirms the molecular formula. Reversed-phase HPLC separates the sample over time, and purity is read as arithmetic: the target peak’s area as a share of total peak area.
Handling & stability
Physical form, storage, and solubility as supplied. Handling guidance only — no use protocols.
Related compounds
Other compounds in this research class.
Frequently asked questions
What is TB-500?
What is the molecular formula of TB-500?
What is the CAS number of TB-500?
How is the identity of TB-500 confirmed?
How should TB-500 be stored?
Is TB-500 a peptide?
Is TB-500 approved for human use?
Data, tools & certificates
Research literature
Research literature — for reference only
Curated peer-reviewed references indexing the identity, characterization, and analytical-method literature for TB-500, from the U.S. National Library of Medicine (PubMed). Listed as neutral citations only — no findings, conclusions, or use are stated or implied.
- Synthesis and characterization of the N-terminal acetylated 17-23 fragment of thymosin beta 4 identified in TB-500, a product suspected to possess doping potential.
- Doping control analysis of TB-500, a synthetic version of an active region of thymosin β₄, in equine urine and plasma by liquid chromatography-mass spectrometry.
- Simplifying and expanding the screening for peptides <2 kDa by direct urine injection, liquid chromatography, and ion mobility mass spectrometry.
- Detecting peptidic drugs, drug candidates and analogs in sports doping: current status and future directions.
- Doping control analysis of seven bioactive peptides in horse plasma by liquid chromatography-mass spectrometry.
References
- PubChem — compound identity, structure & computed properties (CID 16132341). PubChem →
- CAS Registry Number 77591-33-4.
- FDA Global Substance Registration System — UNII 549LM7U24W.
Research professionals only
TB-500 — from the record to the bench
The monograph and every lot certificate stay public. Pricing and ordering open for verified research professionals.