Buy TB-500 Research Peptide

TB-500 (CAS 885340-08-9) is a synthetic heptapeptide corresponding to amino acids 17-23 of Thymosin Beta-4 (Tβ4), with the molecular formula C₃₈H₆₈N₁₀O₁₄ and a molecular weight of 889.02 g/mol. Its sequence, Ac-Leu-Lys-Lys-Thr-Glu-Thr-Gln (Ac-LKKTETQ), features an N-terminal acetylation and comprises the LKKTET actin-binding motif that Thymosin Beta-4 uses to engage G-actin. Originally registered under this CAS number as a short-chain research/veterinary compound, TB-500 is distinct from full-length Thymosin Beta-4 (CAS 77591-33-4, 4963.44 g/mol), which is sold separately on this site. Produced via solid-phase peptide synthesis, TB-500 is studied as an isolated fragment of the actin-binding region rather than the intact 43-amino-acid protein.

Structural mapping of the actin-binding site places the LKKTET motif (positions 17-22) alongside a second, N-terminal region that together mediate Thymosin Beta-4's high-affinity G-actin sequestration [1]. Whether the isolated seven-residue fragment reproduces this full sequestering activity on its own is less established than for the intact protein, but a study directly comparing the two found that an isolated actin-binding-motif peptide reproduced full-length Thymosin Beta-4's activity in endothelial cell migration, adhesion, and angiogenesis assays [2]. Because most of the published mechanistic and animal-model research on this pathway was conducted using the full-length protein, and no human clinical trials have evaluated the isolated fragment itself, TB-500 is supplied strictly for in vitro laboratory research into actin-binding-motif biology, cell migration, and angiogenesis signaling.

TB-500 is manufactured in an ISO9001 certified laboratory to a guaranteed purity of ≥98%. Every batch is independently tested using HPLC and MS-UPLC analysis before dispatch. Vials are vacuum sealed and stored in a temperature controlled, monitored cold storage system to preserve compound integrity throughout the supply chain. Certificates of Analysis are available to view and download directly on the product page.

Sold strictly for in vitro research purposes only. Not for human consumption. Intended for use by qualified researchers in laboratory settings only.

Scientific Review

Dr. Martina Rossi, PhD

Scientific Contributor and Reviewer

Reviewed for scientific accuracy, 14 June 2026

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