| Pack Size | Single Vial, 10-Pack |
|---|
TB-500 Fragment 17-23 is a synthetic seven-residue peptide corresponding to residues 17 through 23 of Thymosin Beta-4, the sequence (LKKTETQ) that constitutes the actin-binding motif of the parent protein. It is studied as the minimal active fragment underlying Thymosin Beta-4's role in actin regulation and cell motility. Every batch is independently third-party tested by HPLC for purity and mass spectrometry for identity, to a minimum of 99 percent purity. Supplied as a lyophilized powder for laboratory research use only.
Description
Thymosin Beta-4 (Tβ4) is a 43-amino-acid actin-sequestering protein central to cytoskeletal research. Structure-function work localised much of its actin-binding activity to a short central motif, the heptapeptide spanning residues 17 to 23 with the sequence Leu-Lys-Lys-Thr-Glu-Thr-Gln (LKKTETQ). TB-500 Fragment 17-23 reproduces this motif as a standalone synthetic peptide.
In the research-supply context, this fragment is studied as the minimal actin-binding element of Thymosin Beta-4, allowing researchers to isolate the contribution of the core motif from the full-length protein or the longer synthetic TB-500 fragment. It is provided strictly as a research-grade reagent for laboratory benchwork.
Mechanism in research literature
The LKKTETQ motif is the segment of Thymosin Beta-4 most closely associated with binding monomeric globular actin (G-actin). In the parent protein this interaction sequesters G-actin and regulates the pool available for filament assembly, influencing cytoskeletal dynamics, cell migration, and the tissue-repair processes for which Thymosin Beta-4 is studied. As an isolated heptapeptide, TB-500 Fragment 17-23 is used to probe how this short motif contributes to actin interaction independently of the rest of the molecule.
Because it represents only the core motif and lacks the full-length structure, the fragment is a mechanistic research tool rather than a substitute for the complete peptide; comparative studies against full-length Thymosin Beta-4 or the longer TB-500 fragment are the standard way it is examined.
Studied properties
Documented areas of research for the actin-binding motif and its parent protein include: G-actin binding and sequestration; regulation of actin-filament dynamics; cell migration and motility; and roles in tissue-repair and wound-healing models. These describe the published research landscape and are provided for scientific context only. They are not claims of efficacy. Ronin Peptides supplies TB-500 Fragment 17-23 exclusively as a research-grade reagent and provides no dosing protocols or therapeutic recommendations.
Compound specifications
| Compound | TB-500 Fragment 17-23 (Thymosin β4 actin-binding motif) |
|---|---|
| Sequence | Leu-Lys-Lys-Thr-Glu-Thr-Gln (LKKTETQ) |
| Molecular weight | approximately 847 g/mol |
| Length | 7 amino acids (heptapeptide) |
| Parent | Residues 17–23 of Thymosin Beta-4 (43 residues) |
| Class | Actin-binding peptide fragment |
| Form | Lyophilized white-to-off-white powder |
| Solubility | Bacteriostatic water; sterile water for injection |
| Vial contents | 10 mg peptide, sealed amber-glass vial under inert gas |
| Purity | ≥99% by HPLC (verified per batch by a third-party analytical lab) |
Storage and handling
Store unopened lyophilized vials dry and cold; long-term storage should be at or below −20 °C, protected from light and moisture. Once reconstituted, keep refrigerated at 2–8 °C and use within a few weeks; avoid repeated freeze–thaw cycles. Bring vials to room temperature before opening.
Compare with similar compounds
TB-500 Fragment 17-23 is the minimal actin-binding motif and is studied against the longer TB-500 fragment and full-length Thymosin Beta-4, which include additional structure beyond the core motif. It is mechanistically unrelated to BPC-157, a pentadecapeptide studied for tissue repair through angiogenic signalling rather than actin binding, although the two are frequently studied together in recovery-research contexts. Researchers choosing between the fragment and the full-length peptide should anchor the decision to whether the isolated motif or the complete molecule is the object of study.
Reconstitution and laboratory handling
A 10 mg vial of TB-500 Fragment 17-23 reconstituted with 2 mL of bacteriostatic water yields a final concentration of 5 mg/mL, or 5,000 mcg/mL. Other diluent volumes scale linearly: 1 mL gives 10 mg/mL, 5 mL gives 2 mg/mL.
- Bring both vials to room temperature before opening.
- Sanitise both rubber stoppers with an alcohol swab.
- Pull the chosen diluent volume into a sterile transfer syringe.
- Direct the water against the inner wall of the peptide vial as it is injected — never onto the lyophilized cake.
- Invert slowly or swirl gently until dissolved. Do not vortex or shake.
- Refrigerate at 2–8 °C.
Frequently asked questions
What is TB-500 Fragment 17-23?
It is a synthetic heptapeptide (LKKTETQ) reproducing residues 17 to 23 of Thymosin Beta-4, the actin-binding motif of the parent protein. It is studied as the minimal active fragment for actin interaction.
How does it differ from standard TB-500?
Standard TB-500 corresponds to a longer fragment of Thymosin Beta-4, while Fragment 17-23 is only the short central actin-binding motif. The fragment isolates that core sequence for mechanistic study.
What is the regulatory status?
Supplied as a research-grade reagent for laboratory use only, not for human or veterinary use.
How is it verified?
Each batch passes through an independent third-party analytical lab for HPLC purity and mass-spectrometry identity confirmation, to a minimum of 99 percent purity.
How do I receive the COA for my batch?
A certificate of analysis is available for your specific batch on request, tied to your lot.
References
- Goldstein AL, Hannappel E, Kleinman HK. Thymosin beta4: actin-sequestering protein moonlights to repair injured tissues. Trends in molecular medicine. 2005. PMID 16099219.
- Huff T et al. beta-Thymosins, small acidic peptides with multiple functions. The international journal of biochemistry & cell biology. 2001. PMID 11311852.
- Van Troys M et al. The actin binding site of thymosin beta 4 mapped by mutational analysis. The EMBO journal. 1996. PMID 8617195.
