TB-500 5mg is a synthetic heptapeptide corresponding to the actin-binding domain of Thymosin Beta-4 (residues 17–23), supplied with N-terminal acetylation and offered exclusively for laboratory, in-vitro research. Rather than the full parent protein, it isolates the short motif that makes contact with the cytoskeleton, giving researchers a defined, reproducible reference fragment to work with in cell-culture and preclinical models. It is not Thymosin Beta-4: the parent protein is 43 residues and about 4,963 Da, while this fragment is 7 residues and 889 Da.

Within the parent protein, this segment forms the principal contact site with monomeric G-actin. The sequestering activity of full-length Thymosin Beta-4 — its ability to shift the G-actin/F-actin equilibrium — is not carried by the motif alone: published structural work locates that activity in the N-terminal segment preceding it, which this fragment does not include. Researchers therefore use the 17–23 fragment as a defined probe of the contact motif itself rather than as a substitute for the parent protein.

Key research areas

  • G-actin binding and cytoskeletal contact mechanisms in cell-culture models
  • Cell migration and cytoskeletal remodeling pathways
  • Tissue-repair and wound-healing research models
  • Angiogenesis and inflammation-response signaling
  • Systemic distribution profiling in preclinical studies

Specifications

  • Amount: 5mg
  • Form: Lyophilized white powder
  • Sequence: Ac-LKKTETQ (N-terminally acetylated heptapeptide)
  • Molecular weight: 889 Da
  • Solubility: Soluble in bacteriostatic water
  • Storage: Refrigerate at 2–8°C

A note on the evidence

The published activity data for this sequence — wound repair, cell migration, angiogenesis — come from studies of the unacetylated peptide LKKTETQ. The N-terminally acetylated form supplied here has been characterised analytically rather than pharmacologically; a 2024 analytical study reported that acetylated LKKTETQ itself showed no significant wound-healing activity in vitro and suggested the reported effects may belong to a metabolite. This material is offered as a defined reference compound for laboratory work, not as a validated bioactive.

Each batch is third-party tested for identity and purity, with a Certificate of Analysis available on request. TB-500 5mg is intended strictly for in-vitro laboratory research use only — not for human or veterinary use, and not for diagnostic or therapeutic purposes.