Also known as: Thymosin beta-4 fragment
A synthetic seven-amino-acid peptide (Ac-LKKTETQ) matching the actin-binding region of the natural protein thymosin beta-4. Direct research on TB-500 itself is very limited; most published work concerns the full parent protein.
TB-500 corresponds to residues 17–23 of thymosin beta-4, the region that binds actin [1]. The full parent protein binds G-actin 1:1 and regulates actin filament turnover, which affects how cells move [2]. A 2024 rat and cell study found TB-500 is broken down into shorter fragments, and only one of them (Ac-LKKTE) showed wound-closure activity in fibroblasts, suggesting earlier activity may come from a metabolite rather than the parent peptide [3].
| Study | Model | Reported result | Source |
|---|---|---|---|
| TB-500 metabolism in rats [3] | Rat Rats given TB-500, urine sampled over 72 hours; plus serum and enzyme incubations | Main metabolite Ac-LK peaked at 0–6 h; Ac-LKK detectable up to 72 h | Peer-reviewed J Chromatogr B 2024 |
| Fibroblast wound-scratch assay [3] | Cell Fibroblast cultures, TB-500 and its metabolites | No cytotoxicity found; only the metabolite Ac-LKKTE showed significant wound-closure activity vs control; parent TB-500 did not | Peer-reviewed J Chromatogr B 2024 |
| Thymosin beta-4 and actin [2] | Review Review of the full parent protein | Summarizes actin binding and studies of the parent protein in wound, cornea, hair-follicle, heart and other models | Peer-reviewed Curr Protein Pept Sci 2023 |
| Parent protein, heart model [4] | Mouse Coronary-ligation model with virus-delivered thymosin beta-4 (full protein, not TB-500); plus cardiac cell cultures | Lower oxidative-damage, inflammation and fibrosis markers vs untreated models; not a study of the TB-500 fragment | Peer-reviewed Cardiovasc Ther 2022 |
Human trials are listed for research context only; outcomes are reported in the linked publications. Animal and lab results do not establish effects in humans.
PureLab supplies TB-500 for laboratory research. Lot-specific certificates of analysis are posted on the product page as they are issued.
View research-grade TB-500