---
title: "What is the amino acid sequence of TB-500? | Sable Peptides"
description: "TB-500 is a research peptide whose amino acid sequence is on the public registry record. The published sequence is Ac-Leu-Lys-Lys-Thr-Glu-Thr-Gln."
canonical: https://www.sablepeptides.co.uk/questions/tb-500-sequence
publisher: Sable Peptides Limited (UK company 17488610)
note: Research use only. Not for human or veterinary use.
---

# What is the amino acid sequence of TB-500?

TB-500 is a research peptide whose amino acid sequence is on the public registry record. The published sequence is Ac-Leu-Lys-Lys-Thr-Glu-Thr-Gln. Its molecular formula is C38H68N10O14. Its molecular weight is 889.0 g/mol. The CAS Registry Number is 885340-08-9. PubChem CID 62707662 indexes the structure.

Sequence. Ac-Leu-Lys-Lys-Thr-Glu-Thr-Gln

Class. peptide.

Formula. C38H68N10O14.

Mass. 889.0 g/mol.

Analytical note. Identity confirmation by mass spectrometry uses the mass calculated from the formula. Sable's release specification is ≥99% by HPLC with identity confirmed against the expected mass (quality page). Research use only. Not a medicine. Not for human or veterinary use.

## Sources

-   [https://pubchem.ncbi.nlm.nih.gov/compound/62707662](https://pubchem.ncbi.nlm.nih.gov/compound/62707662)

## TB-500: reference facts

8 TB-500 values, each linked to its public source; see the [TB-500 reference page](/ref/tb-500).

| Synonyms | synthetic thymosin beta-4 fragment (Ac-LKKTETQ) (pubchem.ncbi.nlm.nih.gov) |
| --- | --- |
| Compound class | peptide (pubchem.ncbi.nlm.nih.gov) |
| CAS Registry Number | 885340-08-9 (pubchem.ncbi.nlm.nih.gov) |
| Sequence | Ac-Leu-Lys-Lys-Thr-Glu-Thr-Gln (pubchem.ncbi.nlm.nih.gov) |
| Molecular formula | C38H68N10O14 (pubchem.ncbi.nlm.nih.gov) |
| Molecular weight | 889.0 g/mol (pubchem.ncbi.nlm.nih.gov) |
| PubChem CID | 62707662 (pubchem.ncbi.nlm.nih.gov) |
| Storage (lyophilised) | -20 °C, dry, protected from light (sigmaaldrich.com) |

## Calculated sequence properties

Computed from the listed sequence. See the [methodology](/data/methodology).

| Length | 7 residues |
| --- | --- |
| Theoretical pI | 7.36 (calculated from sequence) |
| Net charge at pH 7 | 0 (calculated) |

## Sizes and prices at Sable

| Vial | Price | Per mg | UK same-size check (2026-10-16) |
| --- | --- | --- | --- |
| 2 mg | £14.26 | £7.13 | lowest other £14.95 across 4 UK sellers |
| 5 mg | £13.93 | £2.79 | lowest other £13.95 across 15 UK sellers |
| 10 mg | £10.99 | £1.10 | lowest other £22.95 across 14 UK sellers |
| 15 mg | £57.49 | £3.83 | no same-size match |
| 20 mg | £39.98 | £2.00 | lowest other £40.00 across 1 UK sellers |

Multi-vial pricing on the same item: 3+ vials 10% off, 5+ vials 15% off, 10+ vials 20% off. Every lot has a certificate of analysis: [CoA library](/coa).

## Typical analytical method

| HPLC column | C18 reversed-phase (100-120 A pore) |
| --- | --- |
| Mobile phase | A: water + 0.1% TFA; B: acetonitrile + 0.1% TFA; linear gradient (e.g. 5-65% B over 20-30 min) |
| Detection | 214-220 nm (peptide bond) |

General literature method. The lot CoA records the method actually used. [How to read an HPLC chromatogram](/learn/how-to-read-an-hplc-chromatogram).

## Related questions

-   [What is the difference between BPC-157 and TB-500?](/questions/bpc-157-vs-tb-500-difference)
-   [Is TB-500 a peptide?](/questions/is-tb-500-a-peptide)
-   [What does TB-500 dissolve in?](/questions/tb-500-solubility)
-   [How stable is lyophilised TB-500?](/questions/tb-500-stability-lyophilised)

## Lyophilised storage on file: TB-500

From the Sable storage reference (lyophilised material only; temperature, light, moisture). Literature basis is linked per row. See [peptide storage](/learn/peptide-storage-and-solubility).

| Compound | Lyophilised storage | Light / notes |
| --- | --- | --- |
| TB-500 | -20 C long term (-80 C acceptable), sealed and desiccated; 2-8 C for weeks | protect from light; no specific sequence liabilities identified from sequence data on file (source) |

## Typical analytical method: TB-500

Reference HPLC and MS conditions from the Sable analytical-methods file; a lot's CoA states the method actually used. See [how to read a CoA](/guides/how-to-read-a-coa).

| Compound | HPLC column / detection | MS / expected ion |
| --- | --- | --- |
| TB-500 | C18 reversed-phase (100-120 A pore); 214-220 nm (peptide bond) | ESI-MS (positive mode); LC-MS for identity; [M+1H]1+ ~890.0; [M+2H]2+ ~445.5; [M+3H]3+ ~297.3 |

Research use only. Not a medicine. Not for human or veterinary use.