Tissue Repair Research Peptide
TB-500 is studied for tissue-repair processes. It is based on Thymosin Beta-4, a protein the body produces that helps cells migrate toward a wound and rebuild their internal scaffolding (the actin cytoskeleton). In preclinical models, researchers examine its role in wound-repair models, tissue regeneration, and the formation of new blood vessels.
Type
Synthetic peptide (Thymosin Beta-4 related)
Molecular formula
C212H350N56O78S
Molecular weight
~4,963 g/mol
CAS number
77591-33-4
Amino acids
43
Modification
N-terminal acetylation. TWO DISTINCT ENTITIES are sold under this name: full-length Thymosin beta-4 (Tβ4; 43 residues; CAS 77591-33-4; INN timbetasin) and the actin-binding fragment Ac-LKKTETQ (residues 17-23; CAS 885340-08-9; INN fequesetide). Most published human clinical work used full-length Tβ4 (e.g. RGN-259), not the fragment; the two are not proven equivalent.
Thymosin Beta-4 is the principal intracellular G-actin-sequestering peptide; the LKKTETQ motif is its actin-binding domain. It binds monomeric actin and modulates actin polymerization rather than acting through a cell-surface receptor.
Research Focus
Studied in preclinical wound-healing, tissue-regeneration, angiogenesis and cytoskeletal (actin-dynamics) research.
Lyophilized
-20°C
~24 months desiccated and protected from light.
Reconstituted
2-8°C
typically stable days to a few weeks; avoid freeze-thaw.
Highly water-soluble; protect from light; aliquot; salt form affects exact mass.
Reviews
Kleinman HK, et al. (2023). Int Immunopharmacology — Review of anti-fibrotic mechanisms (full-length Tβ4)
Sosne G. (2018). Expert Opin Biol Ther — Ocular-surface development review (full-length Tβ4)
Dubé KN, Smart N. (2018). Expert Opin Biol Ther — Vasculature and angiogenesis review (full-length Tβ4)
Reviews
Sosne G, Kleinman HK. (2015). Invest Ophthalmol Vis Sci — Repair-mechanism review (full-length Tβ4)
Morris DC, et al. (2012). Ann NY Acad Sci — Neurological-injury models review (full-length Tβ4)
Goldstein AL, et al. (2005). Trends Mol Med — Actin-sequestering and 'moonlighting' review (full-length Tβ4)
Clinical
Also known as: Thymosin beta-4 (full-length), Ac-LKKTETQ (fragment)
Research Use Only
These products are intended for research purposes only and are not for human consumption. Not FDA approved. Not intended to diagnose, treat, cure, or prevent any disease.
Sosne G, et al. (2022). Int J Mol Sci — Phase III RCT in neurotrophic keratopathy (RGN-259, full-length Tβ4)
Sosne G, Ousler GW. (2015). Clin Ophthalmol — Phase 2 RCT in dry eye, CAE model (full-length Tβ4)
Sosne G, et al. (2015). Cornea — Phase 2 RCT in severe dry eye (full-length Tβ4)
Ruff D, et al. (2010). Ann NY Acad Sci — Phase 1 IV safety and PK study in healthy volunteers (full-length Tβ4)
ClinicalTrials.gov. ClinicalTrials.gov — Registered trial — NL005 Phase IIb in acute MI (full-length Tβ4; context only)
ClinicalTrials.gov. ClinicalTrials.gov — Registered trial — ARISE-1 (full-length Tβ4; context only)
ClinicalTrials.gov. ClinicalTrials.gov — Registered trial — ARISE-2 (full-length Tβ4; context only)
ClinicalTrials.gov. ClinicalTrials.gov — Registered trial — RGN-352 Phase 2 (full-length Tβ4; context only)
ClinicalTrials.gov. ClinicalTrials.gov — Registered trial — RGN-137 (full-length Tβ4; context only)
ClinicalTrials.gov. ClinicalTrials.gov — Registered trial — RGN-137 (full-length Tβ4; context only)
ClinicalTrials.gov. ClinicalTrials.gov — Registered trial — RGN-137 (full-length Tβ4; context only)
Primary research
Tan SH, et al. (2021). Theranostics — Porcine MI study with hiPSC-cardiomyocytes (full-length Tβ4)
Li H, et al. (2018). J Gene Med — CCl4 hepatic-fibrosis model (full-length Tβ4)
Hong Y, et al. (2017). Biochem Biophys Res Commun — Liver-fibrosis model, Notch signaling (full-length Tβ4)
Cheng P, et al. (2014). Neuropharmacology — Rat spinal-cord-injury model (full-length Tβ4)
Conte E, et al. (2013). Eur J Clin Invest — Bleomycin lung model (full-length Tβ4)
Wang L, et al. (2012). Neurobiol Dis — Diabetic-peripheral-neuropathy model (full-length Tβ4)
Esposito S, et al. (2012). Drug Test Anal — HPLC/HRMS identification of the active fragment (TB-500 fragment)
Ho ENM, et al. (2012). J Chromatogr A — LC-MS detection of the fragment (TB-500 fragment)
Morris DC, et al. (2010). Neuroscience — Rat embolic-stroke model (full-length Tβ4)
Zhang J, et al. (2009). Neuroscience — Mouse EAE model (full-length Tβ4)
Smart N, et al. (2007). Nature — Epicardial progenitor and coronary-development study (full-length Tβ4)
Philp D, et al. (2007). Ann NY Acad Sci — Hair-follicle stem-cell study (full-length Tβ4)
Bock-Marquette I, et al. (2004). Nature — Integrin-linked kinase, cardiac study (full-length Tβ4)
Philp D, et al. (2004). FASEB J — Hair-follicle stem-cell-activation study (full-length Tβ4)
Xue B, et al. (2004). EMBO J — Actin-sequestration crystal-structure study (full-length Tβ4)
Philp D, et al. (2003). FASEB J — Actin-binding-site angiogenesis study (Tβ4 actin-binding region)
Grant DS, et al. (1999). Angiogenesis — Endothelial-differentiation study (full-length Tβ4)
Weber A, et al. (1992). Biochemistry — 1:1 actin-monomer-sequestration study (full-length Tβ4)
