Thymosin Beta-4 (TB4)
Stocked in 10mg at MontanaPep in Great Falls, Montana. Sold for laboratory research use only.
| Size | Catalog no. | Price per vial |
|---|---|---|
| 10mg | TB410 | $90 |
Classification
Full-length thymosin beta-4 — the complete 43-residue protein, not the TB-500 fragment
Structure and chemistry
Thymosin beta-4 (Tβ4) is a 43-amino-acid protein, acetylated at its N-terminus, with the sequence Ac-SDKPDMAEIEKFDKSKLKKTETQEKNPLPSKETIEQEKQAGES and a molecular weight of about 4,963 daltons (CAS 77591-33-4). In humans it is encoded by the TMSB4X gene. TB-500, also in this catalog, is only residues 17 to 23 of this sequence (Ac-LKKTETQ, about 889 daltons), roughly a fifth of the mass. This listing is the whole protein. The original research material was purified from calf thymus; research-grade thymosin beta-4 today is made by peptide synthesis rather than extracted from animal tissue.
What the published research shows
Thymosin beta-4 is one of the most studied regenerative peptides. Laboratory and animal research covers wound healing, corneal repair, cardiac injury, new blood vessel formation, inflammation and fibrosis. Unlike the TB-500 fragment, the full-length protein has also been tested in human clinical trials: RegeneRx Biopharmaceuticals and its partner ReGenTree studied a 0.1% thymosin beta-4 eye drop called RGN-259 in dry eye disease (ARISE-1, 317 patients, completed 2016; ARISE-2, 601 patients, completed 2017; ARISE-3, a Phase 3 trial begun in May 2019), alongside earlier studies in wound healing and cardiac repair.
Mechanism of action
Thymosin beta-4 is the body’s principal G-actin sequestering molecule, present at roughly 300 to 500 micromolar in the cytoplasm of nearly all mammalian non-muscle cells and binding G-actin in a 1:1 ratio. Beyond holding actin in reserve, the full protein promotes cell migration and new blood vessel formation, dampens NF-κB-driven inflammatory signaling and limits fibrosis. Different regions do different jobs: residues 17 to 23 (LKKTETQ, the TB-500 sequence) carry the actin-binding and cell-migration activity, while the N-terminal Ac-SDKP tetrapeptide released from the full protein is separately antifibrotic. Only the full-length molecule contains all of these regions.
Development history
Teresa L.K. Low, Allan L. Goldstein and colleagues published the complete amino-acid sequence of thymosin beta-4 purified from calf thymus in 1981. In 1991 it was shown to be identical to Fx, the peptide that holds monomeric actin in reserve inside cells. Hynda Kleinman’s group at the National Institutes of Health reported accelerated wound healing in 1999, and a 2004 study in Nature reported improved cardiac repair in mice. RegeneRx Biopharmaceuticals carried the full-length protein into human trials.
Current regulatory status
Not FDA-approved for any indication. The full-length protein reached Phase 3 testing as the RGN-259 eye drop (ARISE-3, begun May 2019). MontanaPep supplies it as a research material for laboratory use only.
Analytical testing
Mass spectrometry should show a mass near 4,963 daltons for the acetylated 43-residue protein; a result near 889 daltons means the vial holds the TB-500 fragment instead, which is the most common mix-up in this category. HPLC purity, confirmation of N-terminal acetylation and net peptide content complete the picture, since a 43-residue synthesis carries more deletion and truncation impurities than a short fragment.
Ordering from Great Falls
MontanaPep, also known as Montana Peptides, is an independently owned supplier based at 715 13th Ave S, Great Falls, Montana. Local pickup is available by arrangement, and we ship to research addresses across Montana including Billings, Missoula, Bozeman, Helena, Butte, Kalispell and Havre. Call (406) 799-0812 or email customerservice@montanapep.com.