Supplied for research purposes only. These peptides are laboratory reagents intended for qualified researchers and educational institutions. Not for human use, animal use, or clinical application.
TB-500 Storage & Stability Datasheet
🖨️ NovaVitality Technical Datasheet
Document ID: NV-DS-TB500-001
Version: 1.0
Effective Date: 10 December 2025
Product: TB-500 (Thymosin Beta-4 Fragment) Research Peptide (RUO)
1. Product Overview
| Parameter | Specification |
|---|---|
| INN (Proposed) | TB-500 (Thymosin Beta-4 1–43 Fragment) |
| CAS Status | 62568-57-4 (assigned) |
| Molecular Formula | C₂₁₂H₃₄₆N₆₂O₆₆S₃ |
| Molecular Weight | 4963.37 g/mol (monoisotopic, N-terminal acetylated) |
| 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-OH |
| (Actin-binding core: Lys¹⁷–Thr²¹ “LKKTET”) | |
| Receptor Profile | Receptor-independent; binds monomeric G-actin (1:1, Kd ≈ 0.6 µM), modulates ILK, PINCH |
| Form Supplied | Lyophilised Solid (white to off-white powder) |
| Purity (HPLC-UV) | ≥98% (gradient elution, C18, 220 nm) |
| Endotoxin | <0.5 EU/mg (LAL kinetic assay) |
| Residual Solvents | Meets ICH Q3C Class 3 limits |
| RUO Status | For research use only — not for human, veterinary, diagnostic, or therapeutic use |
2. Recommended Storage Conditions
✅ Unopened (Lyophilised)
| Condition | Stability Duration | Notes |
|---|---|---|
| −20°C, desiccated, dark | ≥24 months | Preferred. Met⁶ and Lys-rich domain require moisture control. Amber vials with argon headspace. |
| 2–8°C (refrigerated) | ≤6 months | Acceptable for active lab use; monitor for cake collapse. |
| Room Temp (≤25°C) | ≤7 days | For transit only. Avoid humidity >60% RH. |
📌 TB-500 is moderately stable lyophilised, but the Lys-rich domain (12 Lys residues) and Met⁶ are moisture/oxidation-sensitive. NovaVitality uses argon backfilling for all vials.
✅ Reconstituted (Solution)
| Solvent | Short-Term (2–8°C) | Long-Term (−80°C) | Notes |
|---|---|---|---|
| 0.1% acetic acid in 0.9% NaCl | ≤72 hours | ≤6 months (aliquoted) | Preferred — suppresses aggregation of Lys-rich domain |
| Bacteriostatic water (0.9% BA) | ≤48 hours | ≤3 months (aliquoted) | Acceptable; benzyl alcohol does not impair actin binding |
| PBS (pH 7.4) | ≤24 hours | Not recommended | High risk of aggregation (Lys charge neutralisation) |
⚠️ Critical:
– Aliquot before freezing — limit freeze–thaw to ≤3 cycles (irreversible oligomerisation after cycle 3).
– Use low-binding tubes (e.g., LoBind Eppendorf) — Lys-rich peptides adsorb to standard polypropylene.
– Avoid repeated pH shifts — irreversible conformational changes occur above pH 6.5.
3. Stability Indicators & Degradation Risks
| Risk Factor | Effect on TB-500 | Detection Method |
|---|---|---|
| Moisture/heat | Met⁶ oxidation → methionine sulfoxide (+16 Da) | LC-MS: +16 Da peak; ↓ actin binding (pyrene assay) |
| Oxidation (Met⁶) | Sulfoxide formation (reversible with DTT) | LC-MS; bioassay loss (actin polymerisation IC₅₀ shift) |
| Aggregation (Lys domain) | Visible haze, precipitate at pH >6.5 | DLS (>200 nm), SEC-HPLC peak broadening |
| Deamidation (Asn²⁶, Gln residues) | Asp/isoAsp formation (+1 Da) | LC-MS/MS; altered electrophoretic mobility |
| Repeated freeze–thaw | Irreversible dimerisation (>3 cycles) | Loss of G-actin sequestration in pyrene assay |
🔬 Tip: Run a quick pyrene-actin polymerisation assay before critical in vivo studies — functional validation is more sensitive than purity alone.
4. Reconstitution Protocol (Best Practice)
- Equilibrate vial to room temp (15 min) in dark (protect Met⁶).
- Centrifuge briefly (5 sec) to collect powder.
- Add 0.1% acetic acid/saline slowly down vial wall (e.g., 1 mL for 10 mg → 10 mg/mL).
- Gently swirl — do not vortex.
- If undissolved: warm to ≤37°C for 2 min + low-power sonication (≤30 sec, ice-cooled bath).
- Filter through 0.22 µm PVDF (low-protein-binding).
- Aliquot into pre-chilled LoBind tubes, flash-freeze in liquid N₂, store at −80°C.
5. Analytical Verification (Post-Storage)
| Test | Acceptance Criteria | When to Run |
|---|---|---|
| HPLC Purity | ≥95% main peak | After >6 months storage, or pre-critical assay |
| LC-MS Identity | Observed MW 4963.4 ±2.0 Da | Annually, or after suspected oxidation |
| Endotoxin | <5 EU/mL in solution | Before in vivo or primary cell studies |
| Bioactivity (Required) | IC₅₀ ≤ 1.0 µM in pyrene-actin polymerisation assay | For all publication or longitudinal studies |
6. References & Compliance
- Bock SC et al. J Biol Chem. 1989;264(8):4644–4649. DOI: 10.1016/S0021-9258(18)81679-8
- Hannappel E. Vitam Horm. 2007;75:205–234. DOI: 10.1016/S0083-6729(07)75008-3
- ICH Q1A(R2): Stability Testing of New Drug Substances
- USP <1079>: Good Storage and Distribution Practices
- MHRA Guidelines on the Labelling of Unlicensed Medicines (2024) — for reference only (RUO not subject, but aligns with handling ethos)
7. Support & Documentation
📧 Technical queries: [email protected]
🔒 This datasheet is for informational purposes only. NovaVitality makes no warranties, express or implied, regarding fitness for a particular purpose. Researchers bear full responsibility for validation in their experimental context.
