TB-500
TB-500 is the synthetic analogue of Thymosin Beta-4 (Tβ4), a highly conserved, 43-amino-acid peptide belonging to the beta-thymosin family of actin-sequestering proteins. First isolated from thymic ti...
Certificate of Analysis included with every order.
Technical Specifications
| Purity | ≥99% |
|---|---|
| Form | Lyophilized Powder |
| Storage | -20°C |
About This Peptide
TB-500 is the synthetic analogue of Thymosin Beta-4 (Tβ4), a highly conserved, 43-amino-acid peptide belonging to the beta-thymosin family of actin-sequestering proteins. First isolated from thymic tissue, Thymosin Beta-4 is endogenously expressed in virtually all nucleated mammalian cells and is regarded as one of the most abundant intracellular peptides identified to date. TB-500 replicates the biologically active domain of the native protein, retaining the critical actin-binding motif (LKKTETQ) that governs the majority of its characterized molecular interactions. The compound is catalogued under the internal code TB-500 and is supplied by Pepitiva Biolabs at ≥99% purity as a lyophilized powder, requiring storage at −20°C to maintain structural integrity.
Research interest in TB-500 and its parent peptide, Thymosin Beta-4, has expanded considerably over the past two decades. Early investigations focused on the protein's role in actin dynamics and cytoskeletal regulation; however, subsequent preclinical studies revealed a broader functional profile encompassing cell migration, differentiation, angiogenesis, and inflammatory modulation. These observations have positioned TB-500 as a useful research tool for dissecting signaling pathways involved in tissue homeostasis and cellular stress responses. Its small, stable structure and high water solubility make it particularly amenable to in vitro experimental systems.
Structurally, TB-500 is a linear peptide with a molecular weight of approximately 4,963 Da. It lacks disulfide bonds, which contributes to its relative stability under physiological buffer conditions commonly employed in cell culture and biochemical assay formats. The peptide's central LKKTETQ sequence is responsible for G-actin sequestration, competitively inhibiting actin polymerization and influencing downstream cytoskeletal remodeling. As a member of the beta-thymosin family, Thymosin Beta-4 shares structural homology with other family members, enabling comparative studies of conserved and divergent functional elements across species. For research use only. Not for human consumption.
The availability of high-purity, lyophilized TB-500 from a reliable supplier supports reproducible experimental outcomes in studies examining actin biology, extracellular matrix interactions, endothelial biology, and related fields. Researchers investigating the molecular basis of cellular repair processes and wound biology have utilized Thymosin Beta-4 analogues as reference compounds and experimental interventions in controlled preclinical models, underscoring the compound's value as a biochemical research reagent.
Research Applications
≥99% purity. Lyophilized Powder. Storage: -20°C. For research purposes only.
Mechanism of Action
The primary biochemical mechanism of TB-500 centers on its sequestration of monomeric G-actin via the conserved LKKTETQ motif. By binding G-actin, TB-500 reduces the pool of actin available for polymerization into F-actin filaments, thereby attenuating cytoskeletal tension and facilitating cell morphology changes associated with migration and proliferation. This interaction has been mapped to the actin subdomain 1 binding interface and has been characterized through crystallographic and isothermal titration calorimetry studies of the native Thymosin Beta-4 sequence.
Beyond direct actin sequestration, preclinical data indicate that TB-500 modulates downstream signaling cascades including the PI3K/Akt and ILK (Integrin-Linked Kinase) pathways. Activation of ILK in response to Thymosin Beta-4 has been associated with increased expression of VEGF, MMP-2, and other matrix remodeling enzymes in endothelial and fibroblast cell models, suggesting a role in extracellular matrix turnover independent of direct cytoskeletal effects. Additionally, TB-500 has been reported in several in vitro systems to attenuate NF-κB-mediated transcription, providing a mechanistic basis for observed modulation of pro-inflammatory cytokine profiles in macrophage and epithelial cell studies.
In stem and progenitor cell research contexts, Thymosin Beta-4 has been shown to influence the nuclear export and transcriptional activity of MRTF-A (Myocardin-Related Transcription Factor A), a G-actin-sensitive co-activator of serum response factor (SRF) target genes. The sequestration of G-actin by TB-500 promotes cytoplasmic retention of MRTF-A, thereby reducing SRF-driven gene expression programs. This regulatory axis represents a mechanistically distinct pathway through which the peptide may influence cell fate decisions in differentiation models.
Research Applications
TB-500 is utilized across a range of in vitro and preclinical research contexts due to its well-characterized interactions with actin dynamics and associated signaling networks. Representative research application areas include:
- Cytoskeletal Biology: Investigation of G-actin sequestration kinetics, F-actin polymerization assays, and lamellipodia/filopodia formation studies in adherent cell lines.
- Cell Migration and Motility Models: Scratch-wound and Boyden chamber assays employing Thymosin Beta-4 analogues to characterize the role of actin dynamics in directional cell movement.
- Angiogenesis Research: Tube formation assays and endothelial sprouting models examining VEGF modulation and endothelial cell proliferation in response to TB-500 treatment.
- Inflammatory Signaling Studies: Evaluation of NF-κB pathway activity and cytokine secretion profiles in macrophage and epithelial cell systems treated with Thymosin Beta-4 peptides.
- Extracellular Matrix Remodeling: Assessment of MMP expression, collagen gel contraction assays, and fibroblast activation studies to probe matrix remodeling pathways linked to ILK signaling.
- MRTF-A/SRF Transcriptional Regulation: Reporter gene assays and nuclear/cytoplasmic fractionation experiments examining the influence of actin-sequestering peptides on MRTF-A localization and SRF target gene expression in myogenic or cardiac cell models.
Storage & Handling Guidelines
Proper storage and handling are essential to maintain peptide integrity and ensure reliable research results. All Pepitiva Biolabs peptides are supplied as lyophilized (freeze-dried) powder, which provides excellent long-term stability when stored correctly. Store lyophilized peptides at -20°C for long-term storage or 2-8°C for short-term use. Once reconstituted, peptide solutions should be stored at 2-8°C and used within the timeframe specified in the product documentation. Always use sterile bacteriostatic water for reconstitution and handle peptides in a clean laboratory environment to prevent contamination. Avoid repeated freeze-thaw cycles, as thermal stress can cause peptide degradation and loss of biological activity.
Quality Control & Certification
This product is manufactured under strict quality control protocols and has been verified through comprehensive analytical testing. Each batch undergoes reverse-phase HPLC analysis for purity determination and electrospray ionization mass spectrometry (ESI-MS) for molecular identity confirmation. A detailed Certificate of Analysis (COA) is available for download, documenting purity percentage, molecular weight verification, appearance, and recommended storage conditions. Pepitiva Biolabs maintains batch-level traceability from synthesis through delivery, ensuring complete transparency and quality assurance for your research.
Frequently Asked Questions
Is this product approved for human use?
No. This product is intended exclusively for in vitro scientific research and laboratory use. It is not approved for human or veterinary use, not intended for diagnostic or therapeutic purposes, and should not be administered to humans or animals under any circumstances.
How do I reconstitute this peptide?
Add sterile bacteriostatic water slowly to the vial, directing the stream against the glass wall rather than directly onto the lyophilized powder. Gently swirl the vial until the powder is fully dissolved — do not shake vigorously. The recommended reconstitution volume depends on your desired concentration. Refer to the product documentation for specific guidance.
Can I get a Certificate of Analysis (COA)?
Yes. A Certificate of Analysis is included with every order and is also available for download from the product page. The COA documents HPLC purity, mass spectrometry identity confirmation, batch number, production date, and storage recommendations.
For research use only. Not for human consumption.