Actin Sequestration Research | Recovery Peptide Comparison
TB-500 vs Thymosin Beta-4
A research comparison of TB-500 (LKKTET domain fragment of Tβ4) and full-length Thymosin Beta-4. Both bind G-actin through the LKKTET motif — but Thymosin Beta-4 contains the complete 43-amino acid sequence with additional domains that engage wound healing, cardiac, and cell survival pathways beyond actin regulation alone.
TB-500 is the LKKTET-domain fragment — a targeted actin sequestration tool. Thymosin Beta-4 is the full-length sequence with broader biological activity including cardiac protection, PI3K/Akt survival signaling, and additional receptor interactions beyond actin binding. Choose TB-500 for clean actin cytoskeletal research. Choose Thymosin Beta-4 when you need the full sequence biological profile or when studying cardiac or neural applications where non-LKKTET domains are implicated.
| Parameter | TB-500 | Thymosin Beta-4 |
|---|---|---|
| Sequence Completeness | LKKTET domain region | Full 43-AA Tβ4 sequence |
| Actin Sequestration | Primary mechanism | Primary mechanism |
| LKKTET Domain | Yes | Yes |
| N-terminal Region | Not included | Included (Ac-SDKP motif) |
| PI3K/Akt Signaling | Minimal | Via ILK (integrin-linked kinase) |
| Cardiac Research | Limited | Extensive (cardiac progenitor) |
| Cell Migration | Strong | Strong |
| Mechanism Specificity | Narrower (actin only) | Broader (multi-pathway) |
| MW | ~4,964 Da | 4,964 Da |
| Price | $59 | $69 |
| HPLC Purity | ≥99.8% | ≥99.8% |
LKKTET Domain vs Full Tβ4 Sequence
TB-500 and Thymosin Beta-4 share the LKKTET G-actin binding domain — the sequence motif responsible for G-actin sequestration and cell migration effects. This is the source of their mechanistic overlap. But the full Thymosin Beta-4 sequence contains additional N-terminal and C-terminal regions absent in TB-500 that engage pathways beyond actin cytoskeletal regulation.
The N-terminal region of Tβ4 contains the Ac-SDKP tetrapeptide sequence, which has documented anti-fibrotic and pro-angiogenic activity and is released by proteolytic cleavage in vivo. The C-terminal region participates in integrin-linked kinase (ILK) interactions that activate the PI3K/Akt survival signaling pathway — a major cytoprotective cascade implicated in cardiac progenitor cell survival and neural protection that TB-500’s truncated sequence does not engage.
Which to choose: If your research specifically concerns actin cytoskeletal dynamics and cell migration, TB-500’s defined LKKTET sequence provides a cleaner mechanistic tool. If your research extends to cardiac repair, PI3K/Akt signaling, or the full Tβ4 biological profile, Thymosin Beta-4 is required. Both are needed as controls if you intend to attribute effects specifically to the LKKTET domain vs. the full sequence.
Research Applications by Compound
TB-500 primary applications: actin cytoskeletal dynamics (G-actin/F-actin equilibrium studies), directed cell migration assays (wound scratch, Boyden chamber), tissue repair models where actin-mediated migration is the primary endpoint, combination protocols with BPC-157 (see our BPC-157 vs TB-500 guide).
Thymosin Beta-4 primary applications: cardiac repair and progenitor cell research, PI3K/Akt/ILK signaling studies, neural protection and regeneration models, combined actin + Akt pathway research, and any design where the complete Tβ4 biological profile is required. Tβ4 knockout/overexpression model correlations require the full sequence as the matching pharmacological tool.
Research Use Only: All compounds are strictly for laboratory and in vitro research. Not for human use, veterinary use, or any diagnostic or treatment purpose. OligoPoly Labs supplies research-grade peptides exclusively to qualified researchers.
OligoPoly Labs — Houston TX · Research Use Only
TB-500 vs Thymosin Beta-4 — LKKTET Domain vs Full Sequence Research Comparison
TB-500 (LKKTET actin-binding domain fragment, $59) and Thymosin Beta-4 (full 43-AA sequence including PI3K/Akt-engaging domains, $69) share the core actin sequestration mechanism but differ significantly in broader biological activity. Thymosin Beta-4’s N-terminal Ac-SDKP region and ILK-interacting C-terminus extend its activity into cardiac repair and PI3K/Akt survival signaling absent in TB-500. OligoPoly Labs supplies both at ≥99.8% HPLC purity with batch-specific COA documentation from Houston TX.
Research Use Only.
Research Compounds Referenced in This Guide
For Research Use Only · Third-Party Tested · COA Verified · Ships from Houston TX