# Thymosin Beta-4 (Full Length, 43 aa)

> Complete 43-residue acetylated thymosin beta-4 — the intact actin-sequestering protein

All products are sold strictly for laboratory research use only. Not for human or veterinary use.

- Web page: https://peptidemedixeu.com/en/products/thymosin-beta-4-full/
- Brand: Peptide Medix EU
- Category: [Tissue Repair & Healing Peptides](https://peptidemedixeu.com/en/collections/tissue-repair-peptides/)
- Purity: ≥99% by HPLC; lot-matched COA available
- CAS number: 77591-33-4
- from €97 (EUR)

## Sizes and prices (EUR)

| Size | Price | SKU |
| --- | --- | --- |
| 2 mg | €97 | THYMOSIN-BETA-4-FULL-2-MG |
| 5 mg | €191 | THYMOSIN-BETA-4-FULL-5-MG |

_Catalog prices at build time; the web page and checkout are authoritative._

## Specifications

- **CAS number:** 77591-33-4
- **Molecular weight:** 4963.44 g/mol
- **Amino acid sequence:** Ac-Ser-Asp-Lys-Pro-Asp-Met-Ala-Glu-Ile-Glu-Lys-Phe-Asp-Lys-Ser-Lys-Leu-Lys-Lys-Thr-Glu-Thr-Gln-Glu-Lys-Asn-Pro-Leu-Pro-Ser-Lys-Glu-Thr-Ile-Glu-Gln-Glu-Lys-Gln-Ala-Gly-Glu-Ser
- **Chain length:** 43 amino acids, N-terminally acetylated
- **Peptide class:** Beta-thymosin family; G-actin sequestering protein
- **Form:** Lyophilized powder, sealed glass vial with crimped stopper
- **Purity:** ≥99% by HPLC; lot-matched COA available
- **Available sizes:** 2 mg, 5 mg
- **Solubility:** Readily soluble in sterile or bacteriostatic water; highly hydrophilic and acidic
- **Storage (lyophilized):** −20 °C, sealed and protected from light and moisture
- **Storage (reconstituted):** 2–8 °C, protected from light; aliquot for longer holds
- **Key motif:** LKKTETQ actin-binding motif at residues 17–23
- **Relationship to TB-500:** TB-500 is the acetylated 17–23 fragment of this sequence
- **Research areas:** Actin dynamics, cell migration, wound closure, angiogenesis, cardiac and corneal repair

## Description

What you receive here is thymosin beta-4 in full — all 43 amino acids, with the natural N-terminal acetyl group — rather than the seven-residue actin-binding fragment marketed as TB-500. In mammalian cells this protein is among the most abundant inside the cell and is the main sequesterer of G-actin: it binds actin monomers one-to-one, holding back a reserve that controls how fast filaments can grow.

The difference from the fragment is experimentally important. TB-500 copies only the central actin-binding motif, LKKTETQ, while the full protein has further structure linked to interactions beyond actin — with reported partners in cell migration, angiogenesis and inflammatory signalling. To find out whether an effect needs the entire protein or just the motif, you need both molecules, which is why labs normally test them together.

## Frequently asked questions

### What distinguishes this from TB-500?

TB-500 is the acetylated seven-residue fragment covering positions 17–23 of this sequence; this product is the whole 43-residue protein containing that motif plus everything around it. Labs use both to test whether the motif by itself explains a particular effect.

### Why are the vials smaller than those for TB-500?

Making a 43-residue peptide at high purity is much harder than making a seven-residue fragment, so the full-length protein comes in 2 mg and 5 mg vials. In moles the gap is even bigger, as the full protein is roughly five and a half times heavier.

### Which purity data and documents come with it?

HPLC testing to ≥99% plus mass-spectrometric identity for each lot, with its certificate of analysis available. Mass spectrometry is especially important here, as this acidic, disordered protein runs abnormally on gels and size-exclusion columns.

### What is its molecular function?

It captures monomeric G-actin in a one-to-one complex and keeps it out of the polymerising pool, serving as the cell's main actin buffer. That puts it at the heart of research on cytoskeletal dynamics, cell migration and processes relying on fast filament turnover.

### How should it be stored?

Unopened lyophilised vials: −20 °C, away from light and moisture. Reconstituted: 2–8 °C for short studies, or aliquoted and frozen for longer. Avoid repeated freeze–thaw and, in long experiments, watch the internal methionine for oxidation.

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All products offered on this website are intended solely for in-vitro laboratory research and development by qualified professionals. They are not drugs, foods, cosmetics or dietary supplements, and are not intended to diagnose, treat, cure or prevent any disease. Products must not be introduced into humans or animals in any manner. By purchasing, you confirm that you are a qualified researcher and accept full responsibility for handling and storage in accordance with applicable laws.

Peptide Medix EU · https://peptidemedixeu.com/en/products/thymosin-beta-4-full/