TB-500 10mg

What is TB-500 ?

TB-500 is the name used in the research market for synthetic thymosin beta 4 (Tβ4). The material here is the full 43-amino-acid sequence, acetylated at the N-terminus. Thymosin beta 4 is the main actin-binding protein in most animal cells, so published work on it looks at how cells move and how new blood vessels form. Each TB-500 10mg vial holds a white lyophilised powder.

Thymosin beta 4 is the most abundant member of the beta-thymosin family in mammalian tissue. It is found in almost all cells and body fluids. Its best-known job is to bind single actin molecules (G-actin) and hold them in reserve. That controls how quickly the cell can rebuild its internal skeleton when it changes shape or moves. The actin-binding site is a short stretch at residues 17 to 23, with the sequence LKKTETQ.

The name TB-500 has been used for two different materials. Ho and colleagues (J Chromatogr A, 2012) describe a veterinary product sold as TB-500 whose main ingredient is the acetylated seven-residue LKKTETQ fragment. Our certificate lists CAS 77591-33-4 and a molecular weight of 4963.4 g/mol, which are the values for the full acetylated protein. You will also see it written as TB500 or Tβ4.

TB-500 Research Applications

• Actin buffering : Tβ4 binds monomeric G-actin and sets the size of the pool available for filament assembly, which links it to cell shape and motility.
• Cell migration and new vessel growth : Philp and colleagues (FASEB J, 2003) found the LKKTETQ site alone matched the full protein in endothelial migration and chick aortic arch sprouting.
• Signalling beyond actin : Bock-Marquette and colleagues (Nature, 2004) reported activation of integrin-linked kinase and Akt, with more cardiomyocyte and endothelial cell migration and survival in mouse heart studies.
• Human data : thymosin beta 4 has been tested as RGN-259 eye drops. The Phase 2 and Phase 3 trials were randomised, placebo-controlled and double-masked (Sosne et al., Cornea 2015 and Int J Mol Sci 2023). These results cover the eye formulation only. Other routes and endpoints are still preclinical.

Published models include cardiac repair after ischaemic injury, dermal wound closure and corneal epithelial repair. Typical lab endpoints are endothelial and keratinocyte migration, collagen deposition, integrin-linked kinase and Akt activation, and changes in inflammatory cytokines.

TB-500 vs BPC-157

The two are unrelated molecules. TB-500 is a 43-residue, 4963.4 g/mol protein that acts mainly through G-actin binding and cell movement. BPC-157 is a 15-residue, 1419.53 g/mol peptide taken from a protein first characterised in human gastric juice. Its literature centres on VEGFR2 signalling in endothelial cells (Hsieh et al., J Mol Med, 2017) and on the nitric oxide pathway. Because the mechanisms differ, preclinical tissue-repair studies often pair them. TB-500 tends to be chosen when actin dynamics, cardiac or corneal models are the endpoint. BPC-157 is more common in gastric mucosa work and in local tendon or ligament models.

Research Overview

Tβ4 is a 43-residue polypeptide, molecular formula C₂₁₂H₃₅₀N₅₆O₇₈S, acetylated at its N-terminal serine. It is the principal G-actin sequestering molecule in eukaryotic cells. By holding actin monomers in a form that cannot polymerise, it controls the supply the cell draws on when it moves.

Most mechanistic work traces back to the LKKTETQ motif at positions 17 to 23. Philp and colleagues (FASEB J, 2003) found this seven-residue site alone matched the full protein in human endothelial cell migration and chick aortic arch sprouting. Sosne and colleagues (FASEB J, 2010) later mapped further activities onto other short internal sequences of the parent protein.

A second line of work showed that Tβ4 does more than buffer actin. Bock-Marquette and colleagues (Nature, 2004) reported that it activates integrin-linked kinase and Akt. This promoted cardiomyocyte and endothelial cell migration and survival in mouse heart studies, including after coronary artery ligation.

Thymosin beta 4 is one of the few compounds in this class with controlled human data. As RGN-259 eye drops it went through a Phase 2 trial in severe dry eye (Sosne et al., Cornea, 2015). A Phase 3 trial in neurotrophic keratopathy followed (Sosne et al., Int J Mol Sci, 2023). Both trials were randomised, placebo-controlled and double-masked. They tell us about a topical eye formulation and nothing about other routes.

The naming problem matters when comparing sources. Doping-control work by Ho and colleagues (J Chromatogr A, 2012) describes a product sold as TB-500 whose main ingredient is the acetylated LKKTETQ fragment. The CAS number and molecular weight on a certificate show which material a supplier is describing.

Storage and Reconstitution

Keep sealed vials at -20°C, away from light and moisture. Stored this way, the lyophilised powder is stable for up to 24 months. After reconstitution with bacteriostatic water, keep the solution at 2-8°C and use it within 4 weeks. For longer storage, split it into single-use aliquots and freeze them at -20°C. Avoid repeated freeze-thaw cycles, which reduce recovery of intact peptide.

Vials are sold on their own, without bacteriostatic water for mixing or other supplies.

How to reconstitute and handle

• Work aseptically. Wipe the vial stopper with 70% isopropyl alcohol before every needle insertion.

For the full method, see the peptide reconstitution guide and the reconstitution calculator.

Research References

• Thymosin beta4 activates integrin-linked kinase and promotes cardiac cell migration, survival and cardiac repair (Bock-Marquette et al., Nature, 2004)
• The actin binding site on thymosin beta4 promotes angiogenesis (Philp et al., FASEB J, 2003)
• Doping control analysis of TB-500, a synthetic version of an active region of thymosin beta 4 (Ho et al., J Chromatogr A, 2012)

Published research on TB-500 is indexed on PubMed. See our full UK buyer's guide for TB-500 10mg and UK buyer's guide for Peptide Price per mg.