TB-500
Research Overview · Mechanism of Action · Reconstitution Guide
Overview
TB-500 is a synthetic analogue of thymosin beta-4 (Tβ4), a 43-amino acid protein ubiquitously expressed in mammalian cells. Tβ4 is the most abundant intracellular actin-sequestering protein, binding G-actin monomers to regulate the actin cytoskeleton. TB-500 corresponds to the actin-binding domain of Tβ4 (residues 17–23: LKKTETQ) and retains much of the parent molecule's biological activity. It has been studied extensively in wound healing, cardiac repair, and anti-inflammatory models.
Mechanism of Action
TB-500 binds G-actin via its LKKTETQ motif, sequestering monomeric actin and modulating the G-actin/F-actin equilibrium. This promotes cell migration by enabling dynamic cytoskeletal remodeling. TB-500 also upregulates metalloproteinase MMP-2, promotes angiogenesis via VEGF and FGF pathways, and reduces inflammatory cytokine expression (IL-1β, TNF-α). In cardiac models, Tβ4 has been shown to activate epicardial progenitor cells and promote cardiomyocyte survival post-ischemia.
Key Studies & References
Goldstein AL et al. (2012). Thymosin β4: a multi-functional regenerative peptide. Basic properties and clinical applications. Expert Opin Biol Ther 12:37–51.
Sosne G et al. (2010). Thymosin beta 4 and the eye: I can see clearly now the pain is gone. Ann N Y Acad Sci 1194:3–8.
Smart N et al. (2007). Thymosin beta4 induces adult epicardial progenitor mobilization and neovascularization. Nature 445:177–182.
Bacteriostatic Water Reconstitution Guide
Research Use Only — The following reconstitution information is provided for in vitro laboratory research purposes only. Not for human or veterinary use.
Recommended Solvent
Bacteriostatic water (0.9% benzyl alcohol)
Standard Volume
Add 2 mL bacteriostatic water to a 5 mg vial to yield a 2500 mcg/mL solution.
Working Concentration
2500 mcg/mL standard. For lower concentrations, dilute with additional bacteriostatic water.
Storage (Reconstituted)
Reconstituted: 2–8°C, use within 28 days. Lyophilized: -20°C, desiccated.
Stability Window
28 days refrigerated. TB-500's larger size makes it somewhat more susceptible to degradation than smaller peptides — minimize freeze-thaw cycles.
Technique
Inject solvent slowly down the vial wall. Swirl gently. TB-500 is a larger peptide (4963 Da) and may take 2–5 minutes to fully dissolve. Do not shake.
Notes
Due to its size, TB-500 may appear slightly opalescent in solution — this is normal. Discard if visible particulates or significant cloudiness develops.
Research Dosing Reference
The following dosing information is derived from published preclinical research literature and is provided for reference purposes only.
Clinical / Human Research Range
No approved clinical dosing. Equine studies have used 12–20 mg per administration.
Preclinical Models
Rodent studies: 150 mcg to 6 mg/kg, subcutaneous or intraperitoneal. Cardiac models typically use 150–300 mcg/animal.
Calculation Example
For a 2500 mcg/mL solution: a 2.5 mg research dose = 1.0 mL. A 5 mg dose = 2.0 mL.