ACURIS SCIENCE

← Back to Growth Hormone Peptides

TB-500 (Thymosin Beta-4) | CAS: 77591-33-4

CAS Number:
77591-33-4
Chemical Classification:
Research peptide

Search related CAS →

TB-500 (Thymosin Beta-4) (CAS 77591-33-4) supplies the actin-binding motif associated with thymosin beta-4, a peptide context in which cytoskeletal remodeling and cell migration are primary mechanistic hypotheses. Research utility depends on whether the model stresses acute wound closure, chronic fibrosis reversal, or cardiac tissue repair after ischemic insult—each framing yields different interpretive constraints. Experimental use includes corneal scrape assays, cardiac fibroblast scratch-wound migration, and localized intramuscular injection following controlled laceration in rodent soft tissue. Material is released with COA, LC-MS, HPLC, and NMR documentation for controlled laboratory investigation only.

CAS
77591-33-4
Molecular Formula
C212H350N56O78S
Molecular Weight
4963.5 g/mol
Purity
≥98%
Appearance
White lyophilized powder
Storage
Store at -20°C

Analytical Documentation

COA✓ Available
LC-MS✓ Available
HPLC✓ Available
NMR✓ Available

Research Inquiry

Overview

TB-500 is a research peptide corresponding to the active region of thymosin beta-4, a 43-amino-acid actin-binding protein involved in cytoskeletal dynamics, cell migration, and angiogenesis. The commonly studied fragment LKKTETQ represents the core motif responsible for actin sequestration and related regenerative phenotypes in cell culture research. TB-500 enables investigation of G-actin buffering, lamellipodia formation, and endothelial sprouting independent of full-length thymosin beta-4 expression levels. In regenerative research laboratories, TB-500 serves alongside BPC-157 and other cytoskeletal modulators to dissect actin remodeling contributions to tissue repair models in controlled preclinical experiments without implying clinical wound therapy. Supplied at ≥98% purity (C212H350N56O78S; 4963.5 g/mol), this material supports controlled laboratory investigation under research-use-only conditions.

Mechanism of Action

TB-500 binds G-actin through its LKKTET motif, altering the monomeric actin pool available for filament polymerization and thereby promoting cell migration in wound scratch and corneal injury research models. Actin redistribution supports endothelial cell tubulogenesis and keratinocyte locomotion in vitro. TB-500 may upregulate matrix metalloproteinases and reduce inflammatory cytokines in some rodent injury paradigms, linking cytoskeletal dynamics to extracellular matrix turnover. Unlike integrin ligands, the peptide does not engage classical cell adhesion receptors directly. Downstream effects on VEGF and HIF-1alpha pathways appear secondary to migration and angiogenic cell behaviors in research settings.

Receptor Binding & Signaling

TB-500 does not act through a conventional GPCR or receptor tyrosine kinase; primary interaction is with cytoplasmic G-actin via the thymosin beta-4 domain. Off-target receptor binding is minimal in standard panels. Cellular uptake occurs through endocytosis and potentially direct membrane penetration in some cell types studied. Mechanism is defined by protein-protein interaction rather than orthosteric receptor occupancy.

Research Applications

Actin dynamics and cell migration

Fibroblast and keratinocyte scratch assays use TB-500 to quantify migration rates, F-actin staining patterns, and lamellipodia extension in time-lapse microscopy. Latrunculin and cytochalasin controls confirm actin dependency. These cell biology platforms map thymosin beta-4 fragment activity in regenerative research.

Corneal and dermal injury models

Rodent corneal debridement and skin wound research employ TB-500 to measure re-epithelialization rates and angiogenic sprouting histologically. TB-500 supports comparison with full-length thymosin beta-4 protein in controlled animal studies. Endpoints remain preclinical histology and imaging metrics.

Cardiac and vascular remodeling

Ex vivo heart slice and hindlimb ischemia models in research animals explore TB-500 effects on capillary density and perfusion recovery markers. Actin remodeling in endothelial tip cells is assessed by confocal microscopy. Studies contribute to cardiovascular regenerative biology without therapeutic claims.

Stem cell and progenitor mobilization research

TB-500 is used in protocols examining endothelial progenitor cell migration and differentiation in culture, paired with actin polymerization readouts. Researchers test whether actin sequestration peptides influence homing behavior in transplantation research models confined to laboratory investigation.

Molecular Information

Sequence & Chain Summary

LKKTETQ heptapeptide (Thymosin β4 residues 17-23); full TB-500 research material may include extended sequence context.

Modification Type

Unmodified fragment peptide.

Structural Notes

The heptapeptide is small and linear with mass near 774 Da for the core motif; supplied material may reflect related thymosin beta-4 sequences per batch COA. HPLC and MS confirm identity. High purity reduces confounding from truncated synthesis impurities. Batch-specific molecular characterization—including mass confirmation and purity profiling—is available through COA, LC-MS, HPLC, and NMR documentation supplied with TB-500 (Thymosin Beta-4).

Molecular Formula
C212H350N56O78S
Molecular Weight
4963.5 g/mol
Purity Specification
≥98%

Experimental Notes

Stability

Lyophilized TB-500 stable at −20°C. Short peptide susceptible to microbial degradation in reconstituted solutions at room temperature; use sterile technique and refrigeration. Minimal oxidation risk due to lack of cysteine in core motif. Lyophilized TB-500 (Thymosin Beta-4) should be protected from repeated freeze-thaw cycles, moisture, and prolonged exposure to ambient light where applicable. Analytical integrity is best preserved when material is stored under the conditions specified on the certificate of analysis.

Storage Conditions

Store at -20°C. TB-500 (Thymosin Beta-4) is supplied as white lyophilized powder. For long-term archival storage in research inventories, maintain sealed containers with desiccant where recommended and document lot numbers for traceability across experimental runs.

Laboratory Handling

Reconstitute in sterile water or PBS. Avoid vigorous mixing. Aliquot frozen stocks for repeated use. Concentrations in micromolar range typical for cell migration assays. Reconstitute only with appropriate research-grade solvents compatible with your assay format. Allow vials to reach equilibrium before opening, work under clean bench conditions, and label all working solutions with concentration, date, and researcher ID per institutional SOPs.

Related Peptides

Growth Hormone Peptides →Peptide CAS database →

Frequently Asked Questions

Research-focused answers about TB-500 (Thymosin Beta-4). For laboratory use only — not medical advice.

What is TB-500 (Thymosin Beta-4) used for in research?
TB-500 is for regenerative biology research on actin-mediated cell migration and angiogenesis in laboratory models. Not intended for human or veterinary therapeutic use.
How does TB-500 (Thymosin Beta-4) work biologically?
TB-500 modulates G-actin sequestration via thymosin beta-4 domain activity, promoting cell migration and angiogenic behaviors in research models through cytoskeletal remodeling rather than classical receptor agonism.
What receptors does TB-500 (Thymosin Beta-4) interact with?
Primary interaction is with cytoplasmic actin monomers, not a cell surface receptor. Standard GPCR and RTK panels show no meaningful target engagement at research concentrations.
Is TB-500 (Thymosin Beta-4) stable at room temperature?
Lyophilized TB-500 stable at −20°C. Short peptide susceptible to microbial degradation in reconstituted solutions at room temperature; use sterile technique and refrigeration. Minimal oxidation risk due to lack of cysteine in core motif. For short-term laboratory workflows, minimize time at room temperature and return unused material to recommended storage promptly. TB-500 (Thymosin Beta-4) is not formulated for ambient long-term storage.
What is the recommended storage condition for TB-500 (Thymosin Beta-4)?
Store at -20°C. Store lyophilized material in a dedicated −20°C freezer, protect from moisture ingress, and avoid repeated temperature cycling. Reconstituted solutions should be aliquoted and frozen if not used within the validated window of your internal stability study.