What is TB-500?

TB-500 is a synthetic peptide fragment derived from thymosin beta-4 (Tβ4), a 43-amino-acid naturally occurring protein that is the major actin-sequestering molecule in eukaryotic cells. Tβ4 is expressed in most mammalian tissues and plays a role in cytoskeletal organisation, cell migration, and development.

The active peptide fragment represents the actin-binding domain of Tβ4. By mimicking the actin-binding region, TB-500 influences cellular dynamics and migration pathways.

For UK research laboratories, TB-500 serves as a reference compound for studies examining cell motility, cytoskeletal dynamics, and tissue remodelling in controlled in vitro environments.

TB-500 operates through the following mechanism in research models:

Actin Sequestration — TB-500 binds to monomeric G-actin, preventing its polymerisation into F-actin filaments. This regulates the pool of available actin monomers and modulates cytoskeletal dynamics.

Cell Migration — Through its effects on actin dynamics, TB-500 influences cell migration and motility in cellular models. The peptide modulates the formation of lamellipodia and filopodia, structures essential for directed cell movement.

Angiogenic Modulation — In endothelial cell models, TB-500 influences angiogenesis through effects on cell migration and tube formation. The peptide modulates VEGF receptor expression and downstream signalling.

Extracellular Matrix Interactions — The peptide influences cell-matrix adhesion dynamics through modulation of integrin expression and focal adhesion turnover. This affects cell spreading and migration on extracellular matrix substrates.

TB-500 is employed across multiple research domains in UK laboratories:

Cell Migration Studies — Wound healing assays (scratch assays) and transwell migration assays examine TB-500's effects on cell motility in fibroblast, endothelial, and epithelial cell models.

Cytoskeletal Dynamics — Cellular models examine TB-500's effects on actin filament organisation, cytoskeletal architecture, and cell morphology using fluorescence microscopy and live-cell imaging.

Angiogenesis Research — Endothelial cell models (HUVEC) are used to study TB-500's effects on tube formation, cell migration, and angiogenic signalling pathways.

Tissue Remodelling — Fibroblast and keratinocyte co-culture models examine TB-500's effects on extracellular matrix deposition, matrix remodelling, and tissue organisation.

Comparative Tissue Repair Studies — TB-500 is frequently compared to other tissue repair compounds (BPC-157) in cellular migration and matrix remodelling assays.

TB-500 is supplied as a lyophilised powder. Standard laboratory preparation:

• Bacteriostatic water (0.9% benzyl alcohol) recommended for reconstitution
• Typical concentrations: 1–10 mg/mL depending on assay requirements
• Solubility: The peptide is generally soluble in aqueous solutions; gentle vortexing may aid dissolution
• pH: Maintain solutions at pH 6.0–7.5

• Lyophilised powder: −20°C, protected from light
• Reconstituted solution: 2–8°C, protected from light
• Stability: 7–14 days under refrigeration; aliquot and freeze at −20°C for extended studies
• Avoid: Repeated freeze-thaw cycles