Compound monograph
Thymosin beta-4
Thymosin beta-4 is an N-terminally acetylated peptide originally isolated from a thymic tissue fraction and subsequently characterized as a G-actin-sequestering peptide.
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Identity & nomenclature
Thymosin beta-4 is an N-terminally acetylated peptide originally isolated from a thymic tissue fraction and subsequently characterized as a G-actin-sequestering peptide.
Timbetasin is the INN for thymosin beta-4. TB-500 is not this molecule. That name designates a distinct seven-residue fragment, carried separately in PubChem as CID 62707662 with a molecular mass of approximately 889 daltons, against 4963 daltons for the full-length peptide described here; the two records also carry different UNII identifiers. Material sold as TB-500 should be identified against the intended species rather than against this record. The PubChem synonym set for this record also includes a carbon-13-labelled internal standard used in mass spectrometry; that labelled compound has a different exact mass and must not be used as an identity reference for unlabelled material.
Declared aliases and development codes: Thymosin b4, Tbeta4, TB4.
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Molecular properties
| Molecular formula | C212H350N56O78S |
|---|---|
| Molecular mass | 4963 Da |
| CAS Registry Number | 77591-33-4 |
| PubChem CID | 16132341 |
| UNII | 2D5MRE3SSY |
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Structural characteristics
The peptide was isolated from thymosin fraction 5, a mixture of polypeptides, alongside thymosin alpha-1 and polypeptide beta-1. The source review records that none of the isolated peptides proved to be thymic hormones. G-actin sequestration was identified in 1990. The peptide is reported to be unstructured in isolation and to fold into a stable conformation on binding G-actin. Related beta-thymosins have been isolated and sequenced from several species.
Terminal features: N-terminal acetyl.
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Molecular targets & mechanisms
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Analytical considerations
The single sulfur atom corresponds to one sulfur-containing residue; oxidized forms of the peptide are described separately in the literature and are a relevant degradation consideration. The N-terminal acetyl group is part of the declared identity. Reference material should be confirmed as unlabelled, because the PubChem record groups a carbon-13-labelled standard under the same identifier.
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Verified bibliography
- current
- Actin dynamics.current
Pollard TD, Blanchoin L, Mullins RD
Journal of cell science · 2001-01 · Journal Article
- Thymosin beta4 and its posttranslational modifications.current
Hannappel E
Annals of the New York Academy of Sciences · 2010-04 · Review
- The beta-thymosin enigma.current
Sun HQ, Yin HL
Annals of the New York Academy of Sciences · 2007-05-10 · Review
- The anti-inflammatory peptide Ac-SDKP is released from thymosin-β4 by renal meprin-α and prolyl oligopeptidase.current
Kumar N, Nakagawa P, Janic B, Romero CA, Worou ME, Monu SR, Peterson EL, Shaw J, Valeriote F, Ongeri EM, Niyitegeka JM, Rhaleb NE, Carretero OA
American journal of physiology. Renal physiology · 2016-03-09 · Journal Article
- Prolyl oligopeptidase is involved in release of the antifibrotic peptide Ac-SDKP.current
Cavasin MA, Rhaleb NE, Yang XP, Carretero OA
Hypertension (Dallas, Tex. : 1979) · 2004-03-22 · Journal Article
- Thymosin β4 and its degradation product, Ac-SDKP, are novel reparative factors in renal fibrosis.current
Zuo Y, Chun B, Potthoff SA, Kazi N, Brolin TJ, Orhan D, Yang HC, Ma LJ, Kon V, Myöhänen T, Rhaleb NE, Carretero OA, Fogo AB
Kidney international · 2013-06-05 · Journal Article
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Methodology & citation verification
Reference identity is checked against official PubMed metadata. Local deterministic receipts bind each normalized title and canonical metadata record to its verification date. Scientific values remain absent when an authoritative source has not been verified.
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