Thymosin β4: The Actin-Binding Peptide Behind TB-500 Research
Thymosin β4 is a 43-amino-acid peptide first characterised as a major actin-sequestering molecule. Here is what the foundational biochemistry and later reviews describe.
Thymosin β4 (Tβ4) is a small, highly conserved peptide of 43 amino acids that is abundant in many cell types. Materials referred to as "TB-500" are associated in the research market with Tβ4; laboratories should confirm the exact sequence and identity stated on the product documentation, as naming conventions vary.
An actin-sequestering molecule
In 1991 Safer, Elzinga and Nachmias reported in the Journal of Biological Chemistry that Tβ4 and a previously described actin-sequestering peptide, Fx, are indistinguishable. This established Tβ4 as a major molecule that binds monomeric (G-) actin and keeps it from polymerising — a central role in how cells regulate their actin cytoskeleton.
A broader research profile
A 2012 review by Goldstein, Hannappel, Sosne and Kleinman, Thymosin β4: a multi-functional regenerative peptide (Expert Opinion on Biological Therapy), summarises subsequent experimental work. It describes studies of Tβ4 in cell migration, angiogenesis and tissue-repair models, and discusses the basic science underlying these activities.
Analytical notes
- At 43 residues, Tβ4 is long enough that synthesis-related impurities such as deletion sequences become more significant, so purity and identity data are especially relevant.
- Tβ4 contains a methionine residue; oxidised forms (sulfoxides) are a known variant and are one reason storage conditions matter.
Thymosin β4-related materials supplied by ICU RESEARCH are for laboratory research use only.
Scientific references
Primary source: Safer D, Elzinga M, Nachmias VT. Thymosin β4 and Fx, an actin-sequestering peptide, are indistinguishable. J Biol Chem. 1991;266:4029–4032. — Source published 1 March 1991
- Goldstein AL, Hannappel E, Sosne G, Kleinman HK. Thymosin β4: a multi-functional regenerative peptide. Basic properties and clinical applications. Expert Opinion on Biological Therapy 12 (2012) 37–51 — 10 November 2011
- Huff T, et al. Interactions of β-thymosins, thymosin β4-sulfoxide and N-terminally truncated thymosin β4 with actin. Eur J Biochem 230 (1995) 650–657 — 1 June 1995
For laboratory research information only. Not medical advice; no product is intended for human or veterinary use.