TB-500 is a synthetic peptide derived from the active site of naturally occurring peptide thymosin beta-4 (Tβ4), specifically the sequence LKKTETQ, with an artificial acetylation at the N-terminus. It is produced through controlled solid-phase peptide synthesis and supplied by BioLongevity Labs as a lyophilized white powder in a sealed 10mg vial with no added fillers. The molecule is a member of the beta-thymosin family and is defined by its actin-monomer-sequestering activity. It is characterized in laboratory research examining cytoskeletal regulation, endothelial cell migration, and angiogenic signaling.
≥99% Purity
Third-Party Tested
COA Available
U.S. Manufactured
Quantity
In stock
Third-Party Verified Quality
≥99% purity verified through independent UHPLC-MS testing. Certificates of Analysis are available before purchase.
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U.S.-manufactured research-grade
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TB-500 is a synthetic version of Thymosin Beta-4, a naturally occurring 43 amino acid peptide found in virtually all mammalian cells. Thymosin Beta-4 acts as a multifunctional regulatory peptide comprising distinct bioactive regions within its structure: the N-terminal tetrapeptide (Ac-SDKP) mediates anti-inflammatory and antifibrotic activities, amino acids 1-15 inhibit apoptosis and promote cell survival, while the central actin-binding region at residues 17 to 23, LKKTETQ, is the segment studied in actin sequestration, cell migration, and tissue-repair research models.
Two sequence regions carry most of the mechanistic work in the literature. The actin-binding motif LKKTET at residues 17 to 22 mediates G-actin sequestration, and the fragment supplied here, LKKTETQ at residues 17 to 23, carries that motif. The N-terminal tetrapeptide Ac-SDKP is a separately characterized fragment with its own experimental record.
Compound Specifications
Property
Value
Synonyms
TB-500, TB500, Ac-Leu-Lys-Lys-Thr-Glu-Thr-Gln-OH, thymosin beta-4 fragment 17-23
CAS Number
885340-08-9
PubChem CID
62707662
Molecular Formula
C₃₈H₆₈N₁₀O₁₄
Molecular Weight
889.0 g/mol
Monoisotopic Mass
888.4916 Da
Amino Acid Sequence
Ac-LKKTETQ (Ac-Leu-Lys-Lys-Thr-Glu-Thr-Gln)
Sequence Length
7 residues, N-terminally acetylated
Parent Sequence Region
Thymosin beta-4 residues 17 to 23
Actin-Binding Motif
LKKTET (residues 17 to 22 of thymosin beta-4)
Source
Synthetic
InChIKey
ADKDNDYYIZUVCZ-ZQNQAVPYSA-N
UNII
QHK6Z47GTG
Purity
≥99% (HPLC)
Appearance
Lyophilized white powder
Solubility
Soluble in water
Storage
-20°C, protect from light
Storage and Handling
Store the lyophilized compound at -20°C, sealed and protected from light.
After reconstitution, store at 2°C to 8°C and use promptly.
Allow the vial to reach room temperature before opening to limit moisture uptake.
Brief sonication may be required for complete dissolution at higher working concentrations.
Maintain aseptic handling to preserve compound integrity.
Lyophilized Format
This compound ships in lyophilized (freeze-dried) form. Freeze-drying supports long-term storage stability and preserves compound integrity. No fillers are added.
Frequently Asked Questions
What Is TB-500?
TB-500 is a synthetic peptide based on the actin-binding region of thymosin beta-4 (Tβ4), built around the sequence LKKTETQ with an acetylated N-terminus. BioLongevity Labs supplies it as a lyophilized white powder in a sealed 10mg vial for research use only.
Is TB-500 the Same as Thymosin Beta-4?
No. Thymosin beta-4 is a naturally occurring 43-residue peptide, while TB-500 is a shorter synthetic peptide modeled on its central actin-binding region at residues 17 to 23.
What Research Area Is TB-500 Studied In?
TB-500 is characterized in laboratory research on actin-monomer sequestration and cytoskeletal regulation. Studies also examine TB-500 in endothelial cell migration and angiogenic signaling research models.
How Should TB-500 Be Stored?
Store lyophilized TB-500 at -20°C, sealed and protected from light, and let the vial reach room temperature before opening. After reconstitution, keep TB-500 at 2°C to 8°C and use it promptly.
How Is TB-500 Purity Verified?
TB-500 from BioLongevity Labs is verified at ≥99% purity through independent UHPLC-MS testing. Certificates of Analysis are published online, so researchers can review them before purchase.
Research Overview
TB-500 carries the actin-binding motif of thymosin beta-4, and actin binding is where the mechanistic literature sits. Thymosin beta-4 is the most abundant beta-thymosin in mammalian cells and is largely unstructured in aqueous solution. Nuclear magnetic resonance work has shown that the peptide backbone folds on binding to monomeric actin, resolving into a central extended region flanked by two helices [1].
Thymosin beta-4 binds monomeric G-actin in a one-to-one ratio and inhibits its polymerization, which sets the threshold concentration of G-actin available in the cytoplasm and shifts the balance between filament assembly and disassembly [2]. The LKKTET motif within the LKKTETQ fragment is the segment identified with that sequestering interaction.
Reported endpoints in this work are measured in cell-free and cell-based systems under defined laboratory conditions. TB-500 is characterized in that setting for cytoskeletal regulation, endothelial cell migration, and angiogenic signaling research.
References
Domanski M, Hertzog M, Coutant J, Gutsche-Perelroizen I, Bontems F, Carlier MF, Guittet E, van Heijenoort C. (2004). Coupling of folding and binding of thymosin beta4 upon interaction with monomeric actin monitored by nuclear magnetic resonance. Journal of Biological Chemistry. https://doi.org/10.1074/jbc.M311413200
Ying Y, Lin C, Tao N, Hoffman RD, Shi D, Chen Z, Gao J. (2023). Thymosin β4 and Actin: Binding Modes, Biological Functions and Clinical Applications. Current Protein & Peptide Science. https://doi.org/10.2174/1389203724666221201093500
A Certificate of Analysis (COA) is a document that verifies a compound’s identity, purity and quality through independent laboratory testing. Every compound from BioLongevity Labs is third-party tested, and its COA is published here, so researchers can review the testing record before a compound enters a protocol.
Each COA reports results from third-party laboratory analysis, including:
Ultra-high-performance liquid chromatography with mass spectrometry (UHPLC-MS) for purity, measured against a 98% or 99% specification depending on the compound
Mass identification for molecular confirmation and content quantitation
Endotoxin testing by Limulus amebocyte lysate (LAL) or recombinant Factor C (rFC) assay, depending on the laboratory
Visual and physical characterization of the finished material
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AV Analytics certificates carry a search code. Scan the QR code on the certificate to open the laboratory’s verification page, or enter the search code at avanalytical.com/coa-search to pull the official record.
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Scientifically reviewed by Dr. Ky H. Le, MD. Dr. Le is a board-certified family medicine physician with over 20 years of clinical experience. Dr. Le validates the scientific accuracy of all technical content and research citations.
Disclaimer: For Research Purposes Only
This content is provided strictly for research purposes and does not constitute an endorsement or recommendation for the non-laboratory application or improper handling of peptides designed for research. The information, including discussions about specific peptides and their researched benefits, is presented for informational purposes only and must not be construed as health, clinical, or legal guidance, nor an encouragement for non-research use. Peptides described here are solely for use in structured scientific study by authorized individuals. We advise consulting with research experts, medical practitioners, or legal counsel prior to any decisions about obtaining or utilizing these peptides. The expectation of responsible, ethical utilization of this information for legitimate investigative and scholarly objectives is paramount. This notice is dynamic and governs all provided content on research peptides.
