Overview
TB-500 is a synthetic peptide fragment derived from Thymosin Beta-4 (gene symbol TMSB4X), a 43-amino-acid protein endogenous to nearly all human and mammalian cells. The TB-500 fragment corresponds to the active region of Thymosin Beta-4 responsible for monomeric G-actin binding. It is studied as a research reagent for cytoskeletal and cellular-migration investigations and is not approved for human use in any jurisdiction.
Research Context
TB-500 appears in the preclinical literature primarily in cytoskeletal research — investigations of actin-binding kinetics, cellular migration in scratch-wound assays, and integrin-mediated signaling in cultured cell preparations. Standard research models include cultured endothelial cells, fibroblast lines, and capillary tube-formation assays in Matrigel. The peptide’s high water solubility makes it well-suited to standard aqueous buffer systems used in cell-culture protocols, and its larger molecular size relative to BPC-157 places it in a different physicochemical category for purification and storage methodology.
Mechanism Summary (Research Framing)
The published primary mechanism of TB-500 centers on its high-affinity binding to monomeric G-actin via a specific actin-binding motif preserved within the fragment sequence. By sequestering G-actin from the cellular monomer pool, the peptide modulates the dynamic equilibrium between G-actin (monomer) and F-actin (polymer) — the core machinery of cell motility and cytoskeletal remodeling. Secondary research literature investigates TB-500 interactions with cell-surface integrins, vascular endothelial growth factor signaling, and downstream MAPK cascade activation in cultured cell models.
Storage Parameters
Lyophilized TB-500 is stable for 24 months or longer when stored at −20°C in its sealed vial, protected from light and moisture. Brief room-temperature shipping exposure does not compromise integrity. Reconstituted aqueous solutions must be kept refrigerated; aliquot before freezing to avoid repeated freeze-thaw cycles. Detailed COA and lot-specific stability information accompanies each Solira Lab vial. See how Solira verifies every lot →
Related Research Compounds
- BPC-157 — synthetic pentadecapeptide, frequently paired with TB-500 in research literature
- BPC-157 vs. TB-500 comparison — structural and research-pathway differences
- GHK-Cu — copper tripeptide, the third component of the GLOW Stack research blend
