TB-500 Peptide 10mg – Thymosin Beta-4 Fragment

Chemical diagram for TB-500 source: https://en.wikipedia.org/wiki/TB-500#/media/File:TB-500_structure.png

KEY SPECIFICATIONS

PRODUCT OVERVIEW

TB-500 is a synthetic heptapeptide corresponding to the active region (amino acids 17-23) of Thymosin Beta-4 (Tβ4), a naturally occurring 43-amino acid polypeptide highly conserved across mammalian species. This fragment contains the essential actin-binding domain responsible for G-actin sequestration—the mechanism underlying Tβ4’s effects on cell migration, tissue repair, and angiogenesis. Research demonstrates TB-500 binds with high affinity to monomeric G-actin, preventing premature polymerization into F-actin filaments and maintaining a pool of unpolymerized actin for rapid cytoskeletal reorganization. Studies document enhanced keratinocyte and endothelial cell migration with effects comparable to full-length Tβ4. N-terminal acetylation protects against aminopeptidase degradation, enhancing bioavailability. BIONIX supplies TB-500 with ≥99% purity for cytoskeletal dynamics and tissue repair research.

MECHANISM OF ACTION

TB-500 functions as an actin-sequestering peptide, directly regulating cytoskeletal dynamics through high-affinity binding to monomeric G-actin.

G-Actin Sequestration Mechanism:

The actin cytoskeleton exists in dynamic equilibrium between G-actin (monomeric, soluble) and F-actin (filamentous, structural). TB-500 specifically binds G-actin monomers, maintaining availability for rapid reorganization.

Cell Migration Enhancement:

Angiogenic Effects:

Studies demonstrate TB-500 increases endothelial cell migration and accelerates tube formation in Matrigel assays—effects directly correlated with G-actin sequestration activity.

Comparison to Full Thymosin Beta-4:

TB-500 retains essential actin-binding activity while offering practical advantages for laboratory research.

Proposed Mechanism Pathway:

TB-500 → G-Actin Binding → Monomer Sequestration → Actin Pool Maintenance → 
Lamellipodia/Filopodia Formation → Cell Migration Enhancement / 
Endothelial Cell Migration → Tube Formation → Angiogenesis Support

RESEARCH APPLICATIONS

• Wound Healing Models: Primary application for investigating cellular mechanisms of wound repair. Keratinocyte migration studies via scratch assays (wound closure rates), Boyden chambers (chemotactic response), time-lapse imaging (velocity, directionality), and proliferation assays (BrdU incorporation). Fibroblast studies examining migration rates, collagen synthesis, extracellular matrix deposition, and myofibroblast differentiation. Experimental endpoints: wound closure percentage, re-epithelialization, granulation tissue formation, tensile strength.

• Angiogenesis Research: Extensive use in vascular formation assays. In vitro models: tube formation (Matrigel—network complexity, branch points), endothelial migration (cells migrated, velocity), proliferation (cell number), sprouting (3D—sprout length, number). Ex vivo: aortic ring sprouting assays, retinal explant vascularization. In ovo: chorioallantoic membrane (CAM) assays for vessel density and branching quantification. Investigation of whether G-actin sequestration directly correlates with angiogenic capacity.

• Cytoskeletal Dynamics Studies: Molecular tool for actin biology investigation. Actin visualization: phalloidin staining (F-actin), G-actin/F-actin ratio quantification, live-cell dynamics imaging, fluorescent actin incorporation. Molecular analysis: actin polymerization assays (pyrene-actin), G-actin sequestration measurements, cofilin/profilin activity assessment, Rho GTPase pathway analysis. Investigation of actin turnover kinetics and filament organization.

• Inflammation Research: Anti-inflammatory properties investigated in various models: cytokine profiling (TNF-α, IL-6, IL-1β), inflammatory cell infiltration quantification, resolution phase marker analysis, macrophage polarization studies. Effects partially attributed to cytoskeletal changes influencing immune cell function and cytokine secretion.

• Analytical Method Development: TB-500 metabolism and detection active research areas: UHPLC-MS/MS method development, metabolite identification (Ac-LKKTE and others), adsorption characterization, doping control applications, pharmacokinetic profiling. PMID 38382158 documents simultaneous quantification of TB-500 and metabolites.

ANALYTICAL VERIFICATION

BIONIX TB-500 undergoes comprehensive analytical characterization:

• HPLC Analysis: Gradient separation confirms ≥99% purity; separates heptapeptide from impurities and synthesis byproducts • Mass Spectrometry: Exact molecular weight confirmation (889.01 Da) and Ac-LKKTETQ sequence verification including N-terminal acetylation • Amino Acid Analysis: Leu-Lys-Lys-Thr-Glu-Thr-Gln composition quantification • N-Terminal Modification Verification: Acetylation confirmation (stability feature) • Endotoxin Testing: LAL assay for cell culture applications

Physical Characteristics:

DEVELOPMENT STATUS

• Origin: Synthetic heptapeptide fragment of Thymosin Beta-4 (amino acids 17-23); contains essential actin-binding domain • Research History: Extensive investigation in wound healing, angiogenesis, and cytoskeletal dynamics; emerging analytical method development • Mechanism: G-actin sequestration through LKKTETQ sequence; prevents premature F-actin polymerization • Clinical Status: Not FDA or EMA approved; research compound only • Recent Research: 2024 UHPLC-MS/MS metabolite identification (PMID 38382158); adsorption characterization (PMID 28887173); doping control methods (PMID 24906629) • WADA Status: Research compound with doping control analytical methods established (verify current prohibited list)

BIONIX TB-500 is supplied exclusively for laboratory research purposes—not for therapeutic use, human administration, veterinary, or clinical applications.

FREQUENTLY ENCOUNTERED INQUIRIES

How does TB-500 differ from full Thymosin Beta-4?

TB-500 is the active heptapeptide fragment (amino acids 17-23) of the complete 43-amino acid Thymosin Beta-4 protein. Research demonstrates this fragment retains the essential actin-binding activity of the full protein while offering improved stability through N-terminal acetylation and simplified handling due to smaller size (889 Da vs. 4,963 Da). The fragment contains the core LKKTETQ sequence responsible for G-actin sequestration, making it functionally equivalent for actin-related research applications with enhanced practical usability.

What is TB-500’s mechanism of action?

TB-500 enhances cell migration through G-actin sequestration. By binding to monomeric G-actin with high affinity, the peptide maintains a pool of unpolymerized actin available for rapid cytoskeletal reorganization. This enables efficient formation of lamellipodia (leading-edge protrusions) and filopodia (exploratory projections)—cellular structures essential for directed migration. The regulated G-actin/F-actin equilibrium supports coordinated actin polymerization at the leading edge and depolymerization at the trailing edge of migrating cells.

What research models is TB-500 used in?

Primary applications: wound healing models (keratinocyte and fibroblast migration assays, scratch assays, closure kinetics), angiogenesis assays (tube formation, endothelial migration, aortic ring sprouting, CAM assays), cytoskeletal dynamics studies (actin visualization, polymerization assays, Rho GTPase analysis), inflammation research (cytokine profiling, macrophage polarization), and analytical method development (UHPLC-MS/MS, metabolite identification, doping control). All applications restricted to controlled laboratory environments.

What reconstitution method is recommended?

Reconstitute lyophilized powder with bacteriostatic water under sterile conditions. Typical research concentrations: 0.1-1 mg/ml for in vitro experiments. Allow vial to reach room temperature before opening, add solvent gently, swirl until dissolved—avoid vortexing. Reconstituted solution should be aliquoted immediately and stored at -20°C (1-3 months) or -80°C (6-12 months). Working aliquots kept at 2-8°C and used within 7 days.

How stable is TB-500?

N-terminal acetylation significantly enhances stability compared to unmodified fragments by protecting against aminopeptidase degradation. Lyophilized form at -20°C: stable up to 24 months. Post-reconstitution: aliquoted solutions maintain activity 1-3 months at -20°C or 6-12 months at -80°C. Working solutions at 2-8°C: use within 7 days. This stability profile enables extended research protocols without degradation concerns affecting reproducibility.

Is TB-500 approved for clinical use?

Negative. TB-500 is a research compound derived from Thymosin Beta-4, not FDA or EMA approved for therapeutic indications. It is investigated exclusively in preclinical and in vitro models for understanding actin dynamics, cell migration, and tissue repair mechanisms. Analytical methods for detection have been developed for doping control purposes (PMID 24906629). BIONIX supplies research-grade material for laboratory use only—not for human therapeutic application.

REFERENCES

• PMID: 38382158 — Simultaneous quantification of TB-500 and metabolites by UHPLC-Q-Exactive orbitrap MS/MS (J Chromatogr B, 2024)
• PMID: 28887173 — Adsorption effects of TB-500 and other doping-relevant peptides (Anal Biochem, 2017)
• PMID: 24906629 — Analytical approaches for detection in human doping controls (J Pharm Biomed Anal, 2014)
• PMID: 15037014 — Thymosin β4 promotes angiogenesis and wound healing (Mech Ageing Dev, 2004)
• Goldstein AL, Kleinman HK., 2015 — Thymosin β4: Actin-sequestering protein repairs injured tissues (Trends Mol Med)
• PMC, 2021 — Utilizing Thymosin Beta-4 to remind adult organs of embryonic state