TB-500 is a synthetic, N-acetylated seven-amino-acid peptide (Ac-Leu-Lys-Lys-Thr-Glu-Thr-Gln) corresponding to the central actin-binding domain — residues 17 to 23 — of the 43-residue regulatory protein thymosin β4. In cell-culture and animal research it is studied as the minimal fragment that reproduces thymosin β4’s actin-sequestering, cell-migration, angiogenic, and tissue-repair activities, and most published “TB-500” functional data in fact derives from work on the full-length thymosin β4 protein.
TB-500 is one of the most widely discussed peptides in tissue-repair research — and also one of the most widely misdescribed. It is not a 43-amino-acid protein, and it is not thymosin β4 itself. TB-500 is the short, synthetic, acetylated fragment Ac-Leu-Lys-Lys-Thr-Glu-Thr-Gln (Ac-LKKTETQ) that corresponds to the central actin-binding domain, residues 17 to 23, of thymosin β4.[1][2] Understanding that fragment-versus-protein relationship is the single most important thing for interpreting the TB-500 literature correctly, because the great majority of published functional data attributed to “TB-500” was generated with full-length thymosin β4.[3]
This guide covers TB-500‘s precise molecular identity and how it differs from the parent protein, the actin-regulation mechanism the fragment is built around, the published thymosin β4 research across wound, cardiac, and tissue-repair models, and how it compares with other reagents in the Apex tissue-repair research cluster within the Apex Research Library. Every factual claim is referenced to the primary literature, and TB-500 is supplied strictly as a research-grade chemical reagent for in-vitro and preclinical investigation — not a drug, supplement, or therapy for human or veterinary use.
TB-500 at a Glance
- TB-500 is the synthetic, N-acetylated 7-residue peptide Ac-Leu-Lys-Lys-Thr-Glu-Thr-Gln (Ac-LKKTETQ) — the central actin-binding domain (residues 17–23) of thymosin β4.
- It is not the full 43-residue thymosin β4 protein. TB-500 has a molecular weight of approximately 889 g/mol (CAS 885340-08-9); thymosin β4 is approximately 4,963 g/mol (CAS 77591-33-4). These are routinely conflated — this guide keeps them distinct.
- The LKKTETQ motif is the experimentally validated active region responsible for thymosin β4’s actin-binding, angiogenic, wound-healing, and cell-migration activity.
- Thymosin β4 is the major intracellular G-actin-sequestering peptide in most vertebrate cells; this actin regulation underlies the cell-migration and tissue-repair phenotypes studied in the literature.
- Most published “TB-500” functional data is in fact thymosin β4 research; this guide labels protein-derived findings as such throughout.
- TB-500 has no FDA-approved formulation and the substance is prohibited in sport by the World Anti-Doping Agency; Apex supplies it strictly as a ≥99% (HPLC + MS verified) research reagent for in-vitro and preclinical use only.
TB-500 (Thymosin β4 Fragment 17–23)
What Is TB-500? Molecular Identity
TB-500 is a synthetic peptide of seven amino acids, acetylated at its N-terminus: Ac-Leu-Lys-Lys-Thr-Glu-Thr-Gln. Its sequence is identical to residues 17 through 23 of thymosin β4, the small regulatory protein that is the major actin-sequestering molecule in most mammalian cells.[3] The fragment carries a molecular weight near 889 g/mol and the molecular formula C38H68N10O14 (PubChem CID 62707662); it is typically supplied as the acetate salt of the free-acid peptide, CAS 885340-08-9.
TB-500 (Ac-LKKTETQ) structure. The seven-residue acetylated fragment corresponding to the actin-binding domain of thymosin β4. Structure image: PubChem CID 62707662, U.S. National Library of Medicine (public domain).
The LKKTETQ Active-Site Domain
The reason a seven-residue fragment is studied at all is that thymosin β4’s biological activity localizes to this short motif. Sosne and colleagues showed that a short sequence containing LKKTETQ — the central actin-binding domain (amino acids 17–23) plus the additional glutamine — promotes angiogenesis, wound healing, and cell migration, reproducing key activities of the intact protein.[1] Earlier mapping work by Philp and colleagues reached the same conclusion from a different direction: the central actin-binding domain, residues 17–23, carried essentially all of the protein’s activity for matrix-metalloproteinase induction in repair-relevant cell types.[2] TB-500 is, in effect, that active region isolated and stabilized by N-terminal acetylation.
Why the Fragment-Versus-Protein Distinction Matters
This distinction is not pedantry. A great deal of published material describes “TB-500” using the molecular weight (~4,963 g/mol), formula, and CAS number (77591-33-4) of the full 43-residue thymosin β4 protein. Those values belong to the parent protein, not to the Ac-LKKTETQ fragment, whose weight is roughly 889 g/mol. For a researcher, the consequence is concrete: identity confirmation by mass spectrometry, dose calculations, and interpretation of any binding stoichiometry all depend on knowing which molecule is actually in the vial. Throughout this guide, mechanism and application data generated with the intact protein are attributed to thymosin β4 (Tβ4), and findings specific to the short fragment are flagged as such.
TB-500 vs Thymosin Beta-4: Fragment vs Parent Protein
Thymosin β4 is a 43-residue, acidic, intrinsically disordered peptide first isolated from calf thymus and originally proposed as a thymic hormone. It is now understood as the principal intracellular G-actin-sequestering peptide of vertebrate cells.[4] TB-500 reproduces the actin-binding portion of that protein in a much smaller, synthetically tractable form. The table below summarizes the relationship.
TB-500 (Ac-LKKTETQ) vs Full-Length Thymosin β4
| Attribute | TB-500 (fragment) | Thymosin β4 (parent protein) |
|---|---|---|
| Length | 7 residues (Ac-LKKTETQ; Tβ4 aa 17–23) | 43 residues (Ac-SDKP…GES) |
| Molecular weight | ≈889 g/mol | ≈4,963 g/mol |
| CAS | 885340-08-9 | 77591-33-4 |
| PubChem CID | 62707662 | 45382195 |
| Source of most data | Bridged via LKKTETQ active-site studies | Bulk of the published functional literature |
| Core activity | Actin-binding motif (LKKTETQ) | G-actin sequestration + additional domains (e.g. N-terminal Ac-SDKP) |
| Regulatory status | Research-only; WADA-prohibited substance | Research reagent; investigational drug (e.g. RGN-259) in trials |
One practical implication of the size difference: the full protein contains sequences beyond the actin-binding domain — most notably the N-terminal tetrapeptide Ac-Ser-Asp-Lys-Pro (Ac-SDKP), which has its own anti-fibrotic and angiogenic literature — that the LKKTETQ fragment does not include. A researcher relying on the fragment should not assume it reproduces every activity of the intact protein, only those that map to the actin-binding region.
Discovery and Research History
From “Thymic Hormone” to Actin-Sequestering Peptide
Thymosin β4 was first described in the search for thymic hormones, but its biological identity changed decisively when Safer and colleagues established that it forms a 1:1 complex with monomeric (G-)actin, maintaining a reservoir of unpolymerized actin and inhibiting its assembly into filaments.[5] Hannappel’s review traced this reframing — from putative hormone to the main intracellular G-actin-sequestering peptide of most vertebrate cells, and later to a cytokine-like factor supporting wound healing.[4] Goldstein and colleagues synthesized the modern view: thymosin β4 is the major actin-sequestering molecule in eukaryotic cells and a key player in dermal and corneal wound healing and the repair of injured solid organs.[3]
Mapping Activity to the LKKTETQ Fragment
The step that makes TB-500 meaningful as a reagent was the localization of activity to the actin-binding domain. Philp and colleagues demonstrated that residues 17–23 carried the protein’s matrix-metalloproteinase-inducing activity,[2] and Sosne and colleagues confirmed that the LKKTETQ-containing short peptide drove angiogenesis, wound healing, and cell migration.[1] Together these studies justify studying the isolated fragment as a proxy for the actin-related activities of the parent protein — while remaining explicit that it is a proxy, not the whole molecule.
Mechanism of Action: Actin Regulation and Repair Signaling
TB-500’s mechanism is, at its core, the mechanism of thymosin β4’s actin-binding domain: it influences the balance between monomeric and filamentous actin, and through that balance it shapes cell migration, angiogenesis, and the repair phenotype.
G-actin sequestration → cell migration, angiogenesis, and repair signaling
The LKKTETQ actin-binding domain that defines TB-500 lets thymosin β4 bind monomeric G-actin in a 1:1 complex, maintaining a mobilizable pool of unpolymerized actin and tuning the G-actin/F-actin balance that drives cytoskeletal remodeling. Downstream, the parent protein acts as a chemoattractant for endothelial cells, keratinocytes, and other repair-relevant cells, promotes angiogenesis (in part through VEGF-dependent paracrine signaling), and engages survival pathways such as PINCH–ILK–Akt in cardiac models. All effects summarized here derive from in-vitro and animal research on thymosin β4 and its active fragment.
G-Actin Sequestration and Cytoskeletal Dynamics
The foundational activity is monomer sequestration. Thymosin β4 binds actin monomers stoichiometrically and maintains the bulk of the cellular actin-monomer pool, inhibiting nucleotide exchange and polymerization.[6] Structural work shows it binds in an extended conformation that contacts both ends of the monomer, and that binding induces a defined subdomain rotation in actin that underpins its high-affinity sequestration.[5][7] In living cells, thymosin β4 levels set the G-actin/F-actin ratio: raising the peptide increases the unpolymerized pool and triggers coordinated cytoskeletal and adhesion changes.[8]
Cell Migration
Actin regulation translates directly into motility. Thymosin β4 acts as a chemoattractant that stimulates directional endothelial-cell migration several-fold over control and accelerates scratch-wound closure.[9] In skeletal-muscle injury models the peptide is upregulated and accelerates the chemotaxis of myoblasts and satellite-cell-derived myocytes, linking actin dynamics to tissue regeneration.[10]
Angiogenesis and VEGF Signaling
Thymosin β4 is pro-angiogenic. Grant and colleagues reported that exogenous thymosin β4 enhances endothelial differentiation and angiogenesis, increasing in-vitro tube formation and vascular sprouting.[11] More recent work describes a VEGF-dependent paracrine mechanism in which thymosin β4 raises VEGF expression in endothelial progenitor cells via the Akt/eNOS pathway,[12] and shows the peptide enhancing endothelial viability, tube formation, and VEGFA expression in a critical-limb-ischemia model.[13]
Anti-Inflammatory Signaling
Beyond actin and angiogenesis, thymosin β4 modulates inflammation. Qiu and colleagues reported that it directly targets the NF-κB RelA/p65 subunit to inhibit TNF-α-induced NF-κB activation and downstream IL-8 transcription,[14] and in corneal epithelial cells it suppresses TNF-α-induced p65 phosphorylation and nuclear translocation.[15] This anti-inflammatory arm complements the migratory and angiogenic activities in the repair models discussed below.
Published Research: Key Application Areas
The thymosin β4 literature is deepest in wound healing and cardiac repair, with additional bodies of work in tendon/muscle and hair-follicle biology. All findings below are research results in cells or animals (or, where noted, investigational-drug trials of the protein), not demonstrated effects of TB-500 in humans.
Dermal and Corneal Wound Healing
Wound healing is the best-developed application. Malinda and colleagues showed that topical or intraperitoneal thymosin β4 accelerates dermal wound healing in a rat full-thickness model, increasing reepithelialization by roughly 42% at day 4 and up to 61% at day 7.[16] The mechanism involves upregulation of matrix metalloproteinases (MMP-1, -2, -9) across keratinocytes, endothelial cells, and fibroblasts, with the central actin-binding domain again identified as the active region.[2] In the eye, thymosin β4 has advanced furthest: randomized, placebo-controlled Phase 2 trials of a 0.1% thymosin β4 ophthalmic solution (RGN-259) in dry-eye disease reported significant reductions in corneal staining and ocular discomfort.[17][18] Those trials studied the full protein as an investigational drug and are cited here as research context, not as evidence for any use of the TB-500 reagent.
Cardiac Repair and Cardioprotection
A landmark 2004 study by Bock-Marquette and colleagues, published in Nature, reported that thymosin β4 promotes myocardial and endothelial cell migration and cardiomyocyte survival by forming a complex with PINCH and integrin-linked kinase (ILK) that activates Akt, improving cardiac function after coronary injury.[19] Srivastava and colleagues extended the cardioprotective account through the same PINCH–ILK–Akt axis,[20] and tissue-engineering work showed that controlled release of thymosin β4 from an injectable collagen–chitosan hydrogel enhanced angiogenesis and reduced post-infarct remodeling in animal hearts.[21]
Tendon, Ligament, and Muscle Repair
The actin-and-migration mechanism is also studied in musculoskeletal repair. Local administration of thymosin β4 improved ligament healing after medial-collateral-ligament transection in rats, producing more uniform collagen-fiber bundles and increased collagen organization,[22] while the muscle-injury work noted above tied the peptide to satellite-cell and myoblast chemotaxis during regeneration.[10]
Hair-Follicle Research
Thymosin β4 has a distinct hair-biology literature. Philp and colleagues reported that it stimulates hair growth in rats and mice by promoting the migration and differentiation of hair-follicle bulge-region stem cells and increasing MMP-2 secretion,[23][24] and later work linked this to upregulation of VEGF and MMP-2 through Wnt/β-catenin/Lef-1 signaling, with thymosin β4 knockout sharply reducing both factors.[25]
TB-500 vs Other Tissue-Repair Research Peptides
TB-500 is frequently studied alongside other tissue-repair reagents that reach overlapping repair endpoints through different mechanisms. For broader context see the tissue-repair research peptides hub and the BPC-157 vs TB-500 comparison.
TB-500 vs BPC-157 vs GHK-Cu: Tissue-Repair Research Peptides
| Attribute | TB-500 | BPC-157 | GHK-Cu |
|---|---|---|---|
| Size | 7-aa fragment (Ac-LKKTETQ) | 15-aa pentadecapeptide | Tripeptide + Cu(II) |
| Primary reported mechanism | Actin sequestration & cell migration | NO-system / VEGF & growth-factor signaling | Copper-dependent ECM synthesis & MMP modulation |
| Key research focus | Migration, angiogenesis, cardiac & corneal repair | Cytoprotection, gut & tendon repair models | Collagen, GAGs, antioxidant, gene expression |
| Origin | Fragment of thymosin β4 | Fragment of a gastric protein (BPC) | Endogenous plasma copper peptide |
| Regulatory status | Research-only; WADA-prohibited | Research-only; no approved drug | Research-only; no approved drug |
TB-500 vs BPC-157
BPC-157 is a 15-residue peptide studied for cytoprotection through nitric-oxide-system modulation and VEGF/growth-factor signaling, whereas TB-500’s research narrative centers on actin regulation and cell migration. The two are often studied together — Apex offers a BPC-157/TB-500 blend as a research reagent — on the rationale that recruiting cells to an injury site (a TB-500/Tβ4 emphasis) and locally promoting cytoprotection and vascular support (a BPC-157 emphasis) probe complementary aspects of repair. See the BPC-157 research guide and the BPC-157 vs TB-500 comparison.
TB-500 vs GHK-Cu
GHK-Cu is a copper-binding tripeptide that works on the extracellular matrix — stimulating collagen and glycosaminoglycan synthesis and modulating matrix metalloproteinases — while TB-500/Tβ4 acts intracellularly on the actin cytoskeleton to drive cell migration. In a simplified division of labor, TB-500 research emphasizes moving cells to a repair site while GHK-Cu research emphasizes building and remodeling the matrix there; the GHK-Cu research guide details its copper-dependent mechanism.
Stability, Handling, and Reconstitution (Research Use)
The guidance below concerns laboratory handling of TB-500 as a research reagent. Nothing here is a human dosing, administration, or usage instruction; TB-500 is for in-vitro and preclinical research only.
Lyophilized Storage
Store lyophilized TB-500 at −20°C, protected from light and moisture. As a short, acetylated peptide it is reasonably robust in the dry state; well-stored lyophilized material is expected to remain stable over extended periods. See the Apex peptide storage guide for general principles.
Reconstitution
TB-500 dissolves readily in bacteriostatic water for laboratory preparation. Researchers planning in-vitro concentrations can use the Apex reconstitution calculator and the how to reconstitute peptides protocol; reconstituted solution is held at 2–8°C with freeze-thaw cycling minimized, and longer-term aliquots are frozen at −20°C. These tools support laboratory work and contain no human-use directions.
Identity and Purity Verification (COA, HPLC, MS)
Because “TB-500” is so often conflated with the much larger parent protein, mass-spectrometric identity confirmation is especially valuable here: it distinguishes the ~889-Da fragment from the ~4,963-Da protein unambiguously. Apex supplies TB-500 at ≥99% purity, verified by reversed-phase HPLC for purity and by mass spectrometry for identity, with a per-lot certificate of analysis available through the lab-verified COA archive. Background on interpreting that documentation is provided in the primers on how to read a certificate of analysis and HPLC testing for peptide purity.
Regulatory Status
TB-500 has no FDA-approved formulation and no approved therapeutic indication. The substance is on the World Anti-Doping Agency Prohibited List and is not permitted in sport; this is a factual regulatory point, not a usage statement. Apex supplies TB-500 strictly as a research-grade chemical reagent for in-vitro and preclinical laboratory work, not for human or veterinary use.
Sourcing Research-Grade TB-500
For actin-cytoskeleton, cell-migration, and tissue-repair research, TB-500 should be sourced as documented research-grade material whose identity is confirmed against the seven-residue fragment — not the parent protein — by mass spectrometry. Apex supplies TB-500 as a ≥99%-pure lyophilized peptide, HPLC- and MS-verified, for in-vitro and preclinical use only.
TB-500 (Thymosin β4 Fragment)
Research-grade Ac-LKKTETQ — the seven-residue actin-binding fragment of thymosin β4 — verified to ≥99% purity by HPLC and mass spectrometry, with a per-lot certificate of analysis. Supplied strictly for in-vitro and preclinical research.
View TB-500 →Frequently Asked Questions
What is TB-500?
TB-500 is a synthetic, N-acetylated seven-amino-acid peptide (Ac-Leu-Lys-Lys-Thr-Glu-Thr-Gln, or Ac-LKKTETQ) corresponding to the central actin-binding domain, residues 17 to 23, of the regulatory protein thymosin beta-4. It has a molecular weight of about 889 g/mol and CAS number 885340-08-9. In research it is studied as the minimal fragment that reproduces thymosin beta-4's actin-related, cell-migration, and tissue-repair activities. Apex Laboratory supplies TB-500 as a research-grade chemical reagent for in-vitro and preclinical research only.
Is TB-500 the same as thymosin beta-4?
No. TB-500 is a seven-residue fragment (Ac-LKKTETQ) of thymosin beta-4, not the full protein. Thymosin beta-4 is 43 residues with a molecular weight of about 4,963 g/mol (CAS 77591-33-4), while the TB-500 fragment is about 889 g/mol (CAS 885340-08-9). The two are frequently conflated, and much published material mistakenly assigns the protein's weight and CAS number to TB-500. The fragment reproduces the actin-binding activity of the protein but does not include other regions such as the N-terminal Ac-SDKP tetrapeptide.
What is the molecular weight and sequence of TB-500?
TB-500 has the sequence Ac-Leu-Lys-Lys-Thr-Glu-Thr-Gln (Ac-LKKTETQ), seven residues with an acetylated N-terminus, a molecular formula of C38H68N10O14, and a molecular weight of approximately 889 g/mol (PubChem CID 62707662, CAS 885340-08-9). This sequence corresponds to residues 17 to 23 of thymosin beta-4, the experimentally identified actin-binding domain.
How does TB-500 work?
TB-500 is built around the actin-binding domain of thymosin beta-4, the major G-actin-sequestering peptide in most cells. Thymosin beta-4 binds monomeric actin in a 1:1 complex, maintaining a pool of unpolymerized actin and tuning the actin cytoskeleton (Safer 1997). Through that actin regulation it acts as a chemoattractant that promotes cell migration (Malinda 1997), supports angiogenesis via VEGF-dependent signaling (Grant 1999), and engages survival pathways in cardiac models (Bock-Marquette 2004). These are in-vitro and animal findings, not demonstrated effects in humans.
What is the LKKTETQ peptide and is it the same as TB-500?
LKKTETQ is the central actin-binding motif of thymosin beta-4, residues 17 to 23. TB-500 is essentially this motif isolated as an N-acetylated seven-residue peptide. Studies showed that a short sequence containing LKKTETQ promotes angiogenesis, wound healing, and cell migration (Sosne 2010) and carries the protein's matrix-metalloproteinase-inducing activity (Philp 2006), which is why the isolated fragment is studied as a proxy for the actin-related activities of the full protein.
What research has been done on TB-500 for wound healing?
Wound healing is the most developed area, studied largely with full-length thymosin beta-4. Topical or intraperitoneal thymosin beta-4 accelerated dermal wound healing in a rat full-thickness model, increasing reepithelialization (Malinda 1999), in part by upregulating matrix metalloproteinases during repair (Philp 2006). In the eye, a thymosin beta-4 ophthalmic solution (RGN-259) reduced corneal staining and discomfort in Phase 2 dry-eye trials (Sosne 2015). These are animal and investigational-drug findings, not evidence for use of the TB-500 reagent in humans.
Has TB-500 been studied for cardiac or heart research?
Yes, again largely as thymosin beta-4. A 2004 Nature study reported that thymosin beta-4 promotes cardiomyocyte and endothelial migration and survival by activating Akt through a PINCH-ILK complex, improving cardiac function after coronary injury (Bock-Marquette 2004), a mechanism extended by later work (Srivastava 2007). Tissue-engineering studies showed controlled release of thymosin beta-4 enhanced angiogenesis and reduced remodeling after experimental infarction (Chiu 2012). All results are from animal models.
What is the difference between TB-500 and BPC-157?
They reach overlapping repair endpoints through different mechanisms. TB-500 is built on thymosin beta-4's actin-binding domain and is studied for cell migration and angiogenesis, while BPC-157 is a fifteen-residue peptide studied for cytoprotection through nitric-oxide-system and VEGF signaling. They are often investigated together, and a BPC-157/TB-500 blend is offered as a research reagent on the rationale that they probe complementary aspects of tissue repair. Both are research-only with no approved drug formulation.
How is TB-500 stored and reconstituted for research?
Lyophilized TB-500 is stored at minus 20 degrees Celsius, protected from light and moisture, where the dry peptide is reasonably stable. For laboratory use it dissolves readily in bacteriostatic water; reconstituted material is held at 2 to 8 degrees Celsius with freeze-thaw cycling minimized, and longer-term aliquots are frozen at minus 20 degrees Celsius. These are laboratory-handling conventions only and are not a human dosing or administration instruction.
Is TB-500 approved or legal?
TB-500 is not approved by the FDA, EMA, or any other regulatory authority as a drug and has no approved therapeutic indication. The substance is on the World Anti-Doping Agency Prohibited List and is not permitted in sport. The research-grade TB-500 supplied by Apex Laboratory is intended strictly for in-vitro and preclinical laboratory research and is not for human or veterinary consumption or any clinical use.
How is research-grade TB-500 purity verified?
Research-grade TB-500 is characterized by reversed-phase HPLC, which quantifies purity by separating the intended peptide from synthesis byproducts, and by mass spectrometry, which confirms identity against the expected mass near 889 g/mol. Mass-spec confirmation is especially important for TB-500 because it distinguishes the seven-residue fragment from the much larger thymosin beta-4 protein. Apex supplies TB-500 at greater-than-or-equal-to 99 percent purity with a per-lot certificate of analysis.
Continue Your Research
Related Tissue-Repair Research Guides
Tissue-Repair Research Peptides
The cluster hub situating TB-500 among connective-tissue and repair research reagents.
Open HubBPC-157 Research Guide
The gastric pentadecapeptide studied for cytoprotection and gut/tendon repair, often paired with TB-500.
Read GuideGHK-Cu Research Guide
The copper tripeptide studied for extracellular-matrix remodeling and collagen synthesis.
Read GuideBPC-157 vs TB-500
A direct comparison of two tissue-repair reagents across mechanism and study design.
CompareReferences
All citations were verified against the published record via the NCBI E-utilities API for existence, correct attribution, and support of the associated claim. Each links to its PubMed record.
- Sosne G, Qiu P, Goldstein AL, Wheater M Biological activities of thymosin beta4 defined by active sites in short peptide sequences. FASEB J. 2010;24(7):2144-51. PMID: 20179146
- Philp D, Scheremeta B, Sibliss K, Zhou M, Fine EL, Nguyen M, et al. Thymosin beta4 promotes matrix metalloproteinase expression during wound repair. J Cell Physiol. 2006;208(1):195-200. PMID: 16607611
- Goldstein AL, Hannappel E, Kleinman HK Thymosin beta4: actin-sequestering protein moonlights to repair injured tissues. Trends Mol Med. 2005;11(9):421-9. PMID: 16099219
- Hannappel E beta-Thymosins. Ann N Y Acad Sci. 2007;1112:21-37. PMID: 17468232
- Safer D, Sosnick TR, Elzinga M Thymosin beta 4 binds actin in an extended conformation and contacts both the barbed and pointed ends. Biochemistry. 1997;36(19):5806-16. PMID: 9153421
- De La Cruz EM, Ostap EM, Brundage RA, Reddy KS, Sweeney HL, Safer D Thymosin-beta(4) changes the conformation and dynamics of actin monomers. Biophys J. 2000;78(5):2516-27. PMID: 10777749
- Dedova IV, Nikolaeva OP, Safer D, De La Cruz EM, dos Remedios CG Thymosin beta4 induces a conformational change in actin monomers. Biophys J. 2006;90(3):985-92. PMID: 16272441
- Golla R, Philp N, Safer D, Chintapalli J, Hoffman R, Collins L, et al. Co-ordinate regulation of the cytoskeleton in 3T3 cells overexpressing thymosin-beta4. Cell Motil Cytoskeleton. 1997;38(2):187-200. PMID: 9331222
- Malinda KM, Goldstein AL, Kleinman HK Thymosin beta 4 stimulates directional migration of human umbilical vein endothelial cells. FASEB J. 1997;11(6):474-81. PMID: 9194528
- Tokura Y, Nakayama Y, Fukada S, Nara N, Yamamoto H, Matsuda R, et al. Muscle injury-induced thymosin β4 acts as a chemoattractant for myoblasts. J Biochem. 2011;149(1):43-8. PMID: 20880960
- Grant DS, Rose W, Yaen C, Goldstein A, Martinez J, Kleinman H Thymosin beta4 enhances endothelial cell differentiation and angiogenesis. Angiogenesis. 1999;3(2):125-35. PMID: 14517430
- Zhao Y, Song J, Bi X, Gao J, Shen Z, Zhu J, et al. Thymosin β4 promotes endothelial progenitor cell angiogenesis via a vascular endothelial growth factor‑dependent mechanism. Mol Med Rep. 2018;18(2):2314-2320. PMID: 29956769
- Lv S, Cai H, Xu Y, Dai J, Rong X, Zheng L Thymosin‑β 4 induces angiogenesis in critical limb ischemia mice via regulating Notch/NF‑κB pathway. Int J Mol Med. 2020;46(4):1347-1358. PMID: 32945357
- Qiu P, Wheater MK, Qiu Y, Sosne G Thymosin beta4 inhibits TNF-alpha-induced NF-kappaB activation, IL-8 expression, and the sensitizing effects by its partners PINCH-1 and ILK. FASEB J. 2011;25(6):1815-26. PMID: 21343177
- Sosne G, Qiu P, Christopherson PL, Wheater MK Thymosin beta 4 suppression of corneal NFkappaB: a potential anti-inflammatory pathway. Exp Eye Res. 2007;84(4):663-9. PMID: 17254567
- Malinda KM, Sidhu GS, Mani H, Banaudha K, Maheshwari RK, Goldstein AL, et al. Thymosin beta4 accelerates wound healing. J Invest Dermatol. 1999;113(3):364-8. PMID: 10469335
- Sosne G, Ousler GW Thymosin beta 4 ophthalmic solution for dry eye: a randomized, placebo-controlled, Phase II clinical trial conducted using the controlled adverse environment (CAE™) model. Clin Ophthalmol. 2015;9:877-84. PMID: 26056426
- Sosne G, Dunn SP, Kim C Thymosin β4 significantly improves signs and symptoms of severe dry eye in a phase 2 randomized trial. Cornea. 2015;34(5):491-6. PMID: 25826322
- Bock-Marquette I, Saxena A, White MD, Dimaio JM, Srivastava D Thymosin beta4 activates integrin-linked kinase and promotes cardiac cell migration, survival and cardiac repair. Nature. 2004;432(7016):466-72. PMID: 15565145
- Srivastava D, Saxena A, Michael Dimaio J, Bock-Marquette I Thymosin beta4 is cardioprotective after myocardial infarction. Ann N Y Acad Sci. 2007;1112:161-70. PMID: 17600280
- Chiu LL, Reis LA, Momen A, Radisic M Controlled release of thymosin β4 from injected collagen-chitosan hydrogels promotes angiogenesis and prevents tissue loss after myocardial infarction. Regen Med. 2012;7(4):523-33. PMID: 22817626
- Xu B, Yang M, Li Z, Zhang Y, Jiang Z, Guan S, et al. Thymosin β4 enhances the healing of medial collateral ligament injury in rat. Regul Pept. 2013;184:1-5. PMID: 23523891
- Philp D, Nguyen M, Scheremeta B, St-Surin S, Villa AM, Orgel A, et al. Thymosin beta4 increases hair growth by activation of hair follicle stem cells. FASEB J. 2004;18(2):385-7. PMID: 14657002
- Philp D, St-Surin S, Cha HJ, Moon HS, Kleinman HK, Elkin M Thymosin beta 4 induces hair growth via stem cell migration and differentiation. Ann N Y Acad Sci. 2007;1112:95-103. PMID: 17947589
- Gao XY, Hou F, Zhang ZP, Nuo MT, Liang H, Cang M, et al. Role of thymosin beta 4 in hair growth. Mol Genet Genomics. 2016;291(4):1639-46. PMID: 27130465
Research Use Disclaimer
All TB-500 products and the information in this guide are intended strictly for in-vitro and preclinical laboratory research. TB-500 is a research-grade chemical reagent and is not a drug, dietary supplement, or therapeutic product. It is not approved by the FDA, EMA, or any other regulatory authority for therapeutic use, has no approved drug indication, and is a substance prohibited in sport by the World Anti-Doping Agency. It is not for human or veterinary consumption, diagnosis, treatment, or any clinical use. The mechanistic, wound-healing, cardiac, and tissue-repair findings summarized here derive from cell-culture, animal-model, and (for the parent protein) investigational-drug studies of thymosin β4 and its active fragment; they are presented for research context only and do not constitute therapeutic, efficacy, or safety claims. Researchers are responsible for compliance with all applicable institutional, local, and national regulations governing the acquisition, handling, and use of research chemicals.
