Why does PubMed return so little for TB-500?

It is a development and trade code rather than a term used in research papers. The literature is indexed under thymosin beta-4.

Which paper is the best starting point?

Hannappel's 2007 review in the Annals of the New York Academy of Sciences for orientation; Low 1981 in PNAS for the foundation.

TB-500 in the Published Research

The short answer

Most of the literature is indexed under thymosin beta-4 rather than TB-500, because TB-500 is a supplier-facing development code rather than a term used in research papers. Searching only for TB-500 misses nearly all of it.

Key facts

Primary search term: Thymosin beta-4
Also useful: Tβ4, beta-thymosins, LKKTETQ
TB-500 in PubMed: Rare (it is a trade-side code)
Key review: Hannappel, Ann N Y Acad Sci 2007
Foundational: Low, PNAS 1981
Evidence type: Predominantly preclinical

Why searching for TB-500 fails

TB-500 is a development code that became a product name. Researchers publishing on the molecule write about thymosin beta-4 or its fragments, and index terms follow the science rather than the market. Anyone searching PubMed for TB-500 will find very little and may conclude the literature is thin, when in fact it is substantial under a different name.

What to search instead

Thymosin beta-4 is the primary term. Beta-thymosins covers the wider family. LKKTETQ finds work specifically on the motif, which is the closest match to the fragment itself. Searching all three gives a fair picture, and comparing what each returns is itself informative about how much work concerns the protein versus the peptide.

Research material referenced

TB-500 5mg, third-party HPLC tested

Buy TB-500 · £23.99

The two anchors

Low and colleagues' 1981 PNAS paper established the complete bovine sequence. Hannappel's 2007 review in the Annals of the New York Academy of Sciences covers the beta-thymosin family and is the sensible orientation point for anyone new to the area. Goldstein's 2012 review in Expert Opinion on Biological Therapy covers the regenerative literature.

The question to ask of every paper

Which molecule was administered. Full-length thymosin beta-4 and the LKKTETQ heptapeptide are both in the literature, and papers state which. Given that the commercially interesting findings and the fragment-attributable findings are largely different sets, this single check does more to clarify the evidence than any other.

What the shape of the literature tells you

Decades of work, concentrated in cell biology and preclinical models, with limited human clinical data and no established registered trial programme for the heptapeptide. That is a mature basic-science literature rather than a therapeutic development programme, and reading it as the latter overstates where it has got to.

Frequently asked questions

Why does PubMed return so little for TB-500?: It is a development and trade code rather than a term used in research papers. The literature is indexed under thymosin beta-4.
Which paper is the best starting point?: Hannappel's 2007 review in the Annals of the New York Academy of Sciences for orientation; Low 1981 in PNAS for the foundation.

Extended research context

The TB-500 (Thymosin β4 fragment) deep dive

Deep dive: TB-500 vs full-length Thymosin Beta-4

'TB-500' is a synthetic peptide corresponding to the active 17-amino-acid actin-binding region of the endogenous 43-residue Thymosin Beta-4 protein. The two are not identical. TB-500 lacks the flanking sequence that gives full-length TB-4 additional binding partners. In the research literature, papers use 'Thymosin β4' when they mean the full protein and 'TB-500' or 'AcSDKP fragment' when they mean the shorter synthetic peptide. Reading a CoA carefully to see which molecule is in the vial matters. Mass spec is the definitive check.

Actin-binding as the core mechanism

The N-terminal region of TB-4 (and TB-500 by inheritance) contains the canonical actin-binding motif. This motif sequesters G-actin monomers, modulating the G:F actin equilibrium in cell cultures. That mechanism is why almost every mechanistic paper on TB-500 traces back to cytoskeletal reorganisation, cell migration, and models of tissue repair.

Handling considerations unique to TB-500

TB-500 is a 17-residue peptide with modest amphipathicity; it reconstitutes cleanly in bacteriostatic water but is sensitive to repeated freeze/thaw. Aliquoting into single-use volumes on first reconstitution preserves potency across a batch. HPLC on the batch CoA should show a single dominant peak; a doublet suggests deamidation.

Research applications

▸In vitro actin-polymerisation assays (G:F actin ratio measurement)
▸Cell-migration and wound-scratch assays in fibroblast lines
▸Angiogenesis models: tube-formation and endothelial migration assays
▸Analytical method development for short peptides on RP-HPLC
▸Reference-material comparisons against endogenous Thymosin β4

Handling checklist

✓Store lyophilised vials at −20 °C long-term
✓Reconstitute with bacteriostatic water (0.9% benzyl alcohol)
✓Aliquot immediately to avoid freeze/thaw cycles
✓Refrigerate reconstituted aliquots at 2–8 °C; use within 28 days
✓Confirm mass (~4,963 Da for TB-500) via CoA before study use

Common research-handling mistakes

Learnt from thousands of researcher orders across our UK labs.

✗ Assuming TB-500 = full Thymosin β4

Fix: TB-500 is the 17-residue actin-binding fragment; check the CoA sequence.

✗ Repeated freeze/thaw

Fix: Aliquot at first reconstitution; each cycle degrades yield.

✗ Using tap water

Fix: Use bacteriostatic or sterile water only.

Continue researching

Peer-reviewed guides, comparators and matched reference materials.

Primary sources & clinical trials

Peer-reviewed research and registered trials from PubMed, ClinicalTrials.gov, PubChem, FDA and NIH. All links open in a new tab and point to the primary source, so every claim can be verified at origin.

UKP

Written and reviewed by

The UK Peptides Editorial Team · Research library, UK Peptides

The editorial team is responsible for supplier selection, batch release decisions and the content published in this research library. Every article here is sourced to primary literature and every product page to a signed third-party certificate. Corrections are made in place and the review date updated.

How we write and check this content Report a factual error in this article

More TB-500 (Thymosin β4 fragment) articles

Popular across the research hub

One flagship guide from every other research category.

← Back to Forum