TB-500: research summary
For laboratory research use only. Not for human or veterinary use. This page summarises published literature. It gives no advice on use.
What the literature covers
TB-500 is a synthetic peptide modelled on the actin-binding region of thymosin beta-4 (Tβ4), a 43-residue protein that is one of the main actin-monomer-sequestering proteins in cells.
The underlying literature is about actin biology. It covers the complete amino-acid sequence of thymosin beta-4, how Tβ4 sequesters G-actin, and how profilin and Tβ4 together control actin filament assembly and nucleotide exchange.
TB-500 should not be described as identical to full-length thymosin beta-4. Check the sequence and mass on the lot's Certificate of Analysis to confirm which molecule is supplied.
Key facts
| TB-500 | BPC-157 | |
|---|---|---|
| CAS | 885340-08-9 | 137525-51-0 |
| Formula | C38H68N10O14 | C62H98N16O22 |
| Molecular weight (g/mol) | 889 | 1419.5 |
Source: PubChem CID 62707662.
TB-500 compared with BPC-157
TB-500 and BPC-157 are often paired in catalogues, but they are unrelated. TB-500 derives from thymosin beta-4, an actin-sequestering protein. BPC-157 is a 15-residue peptide described as a fragment of a gastric-juice protein. Their research literatures barely overlap.
Full side-by-side: TB-500 vs BPC-157 · BPC-157 research summary
Frequently asked questions
- Is TB-500 the same as thymosin beta-4?
- No. Thymosin beta-4 is a 43-residue protein. TB-500 is a shorter synthetic peptide based on its actin-binding region.
- What does thymosin beta-4 do in cells?
- It binds monomeric (G-) actin and keeps it from polymerising, which buffers the pool of actin available for filament assembly.
- How do I confirm what TB-500 product I have?
- Compare the mass-spectrometry result on the lot's CoA with the expected molecular weight (about 889 g/mol for the listed TB-500 formula C38H68N10O14).
Published literature cited
- Pantaloni D, Carlier MF. (1993). How profilin promotes actin filament assembly in the presence of thymosin beta 4. Cell. PMID 8252614 · doi:10.1016/0092-8674(93)90544-z
- Safer D, Elzinga M, Nachmias VT. (1991). Thymosin beta 4 and Fx, an actin-sequestering peptide, are indistinguishable. J Biol Chem. PMID 1999398 · doi:10.1016/s0021-9258(20)64278-8
- Goldschmidt-Clermont PJ, Furman MI, Wachsstock D, Safer D, Nachmias VT, Pollard TD. (1992). The control of actin nucleotide exchange by thymosin beta 4 and profilin. A potential regulatory mechanism for actin polymerization in cells. Mol Biol Cell. PMID 1330091 · doi:10.1091/mbc.3.9.1015
- Low TL, Hu SK, Goldstein AL. (1981). Complete amino acid sequence of bovine thymosin beta 4: a thymic hormone that induces terminal deoxynucleotidyl transferase activity in thymocyte populations. Proc Natl Acad Sci U S A. PMID 6940133 · doi:10.1073/pnas.78.2.1162
- Yu FX, Lin SC, Morrison-Bogorad M, Atkinson MA, Yin HL. (1993). Thymosin beta 10 and thymosin beta 4 are both actin monomer sequestering proteins. J Biol Chem. PMID 8416954 · doi:10.1016/s0021-9258(18)54179-x
Every citation was looked up by PMID in Europe PMC (MEDLINE) on 2026-10-14 and its title matched. Citation means the paper exists and is relevant to the compound. It does not mean the paper supports any use.