Thymosin beta 4 acetate
[CAS# 77591-33-4]

Identification

• Classification: Biochemical >> Peptide
• Name: Thymosin beta 4 acetate
• Synonyms: Timbetasin; (4S)-4-[[2-[[(2S)-2-[[(2S)-2-[[(2S)-2-[[(2S)-2-[[(2S)-2-[[(2S)-2-[[(2S,3S)-2-[[(2S,3R)-2-[[(2S)-2-[[(2S)-2-[[(2S)-2-[[(2S)-1-[(2S)-2-[[(2S)-1-[(2S)-2-[[(2S)-2-[[(2S)-2-[[(2S)-2-[[(2S,3R)-2-[[(2S)-2-[[(2S,3R)-2-[[(2S)-2-[[(2S)-2-[[(2S)-2-[[(2S)-2-[[(2S)-2-[[(2S)-2-[[(2S)-2-[[(2S)-2-[[(2S)-2-[[(2S)-2-[[(2S,3S)-2-[[(2S)-2-[[(2S)-2-[[(2S)-2-[[(2S)-2-[[(2S)-1-[(2S)-2-[[(2S)-2-[[(2S)-2-acetamido-3-hydroxypropanoyl]amino]-3-carboxypropanoyl]amino]-6-aminohexanoyl]pyrrolidine-2-carbonyl]amino]-3-carboxypropanoyl]amino]-4-methylsulfanylbutanoyl]amino]propanoyl]amino]-4-carboxybutanoyl]amino]-3-methylpentanoyl]amino]-4-carboxybutanoyl]amino]-6-aminohexanoyl]amino]-3-phenylpropanoyl]amino]-3-carboxypropanoyl]amino]-6-aminohexanoyl]amino]-3-hydroxypropanoyl]amino]-6-aminohexanoyl]amino]-4-methylpentanoyl]amino]-6-aminohexanoyl]amino]-6-aminohexanoyl]amino]-3-hydroxybutanoyl]amino]-4-carboxybutanoyl]amino]-3-hydroxybutanoyl]amino]-5-amino-5-oxopentanoyl]amino]-4-carboxybutanoyl]amino]-6-aminohexanoyl]amino]-4-amino-4-oxobutanoyl]pyrrolidine-2-carbonyl]amino]-4-methylpentanoyl]pyrrolidine-2-carbonyl]amino]-3-hydroxypropanoyl]amino]-6-aminohexanoyl]amino]-4-carboxybutanoyl]amino]-3-hydroxybutanoyl]amino]-3-methylpentanoyl]amino]-4-carboxybutanoyl]amino]-5-amino-5-oxopentanoyl]amino]-4-carboxybutanoyl]amino]-6-aminohexanoyl]amino]-5-amino-5-oxopentanoyl]amino]propanoyl]amino]acetyl]amino]-5-[[(1S)-1-carboxy-2-hydroxyethyl]amino]-5-oxopentanoic acid
• Protein Sequence: SDKPDMAEIEKFDKSKLKKTETQEKNPLPSKETIEQEKQAGES
• Molecular Formula: C₂₁₂H₃₅₀N₅₆O₇₈S
• Molecular Weight: 4963.50
• CAS Registry Number: 77591-33-4
• SMILES: CC[C@H](C)[C@@H](C(=O)N[C@@H](CCC(=O)O)C(=O)N[C@@H](CCCCN)C(=O)N[C@@H](CC1=CC=CC=C1)C(=O)N[C@@H](CC(=O)O)C(=O)N[C@@H](CCCCN)C(=O)N[C@@H](CO)C(=O)N[C@@H](CCCCN)C(=O)N[C@@H](CC(C)C)C(=O)N[C@@H](CCCCN)C(=O)N[C@@H](CCCCN)C(=O)N[C@@H]([C@@H](C)O)C(=O)N[C@@H](CCC(=O)O)C(=O)N[C@@H]([C@@H](C)O)C(=O)N[C@@H](CCC(=O)N)C(=O)N[C@@H](CCC(=O)O)C(=O)N[C@@H](CCCCN)C(=O)N[C@@H](CC(=O)N)C(=O)N2CCC[C@H]2C(=O)N[C@@H](CC(C)C)C(=O)N3CCC[C@H]3C(=O)N[C@@H](CO)C(=O)N[C@@H](CCCCN)C(=O)N[C@@H](CCC(=O)O)C(=O)N[C@@H]([C@@H](C)O)C(=O)N[C@@H]([C@@H](C)CC)C(=O)N[C@@H](CCC(=O)O)C(=O)N[C@@H](CCC(=O)N)C(=O)N[C@@H](CCC(=O)O)C(=O)N[C@@H](CCCCN)C(=O)N[C@@H](CCC(=O)N)C(=O)N[C@@H](C)C(=O)NCC(=O)N[C@@H](CCC(=O)O)C(=O)N[C@@H](CO)C(=O)O)NC(=O)[C@H](CCC(=O)O)NC(=O)[C@H](C)NC(=O)[C@H](CCSC)NC(=O)[C@H](CC(=O)O)NC(=O)[C@@H]4CCCN4C(=O)[C@H](CCCCN)NC(=O)[C@H](CC(=O)O)NC(=O)[C@H](CO)NC(=O)C

Properties

• Solubility: Soluble 0.10 mg/mL (water) (Expl.)

Safety Data

• Hazard Symbols: GHS07 Warning
• Hazard Statements: H302-H315-H319-H335
• Precautionary Statements: P261-P305+P351+P338

Discovory and Applicatios

Somatostatin beta 4 acetate (correctly referred to as thymosin beta 4 or T β4) is a naturally occurring peptide of 43 amino acids that is encoded in humans by the TMSB4X gene and is one of the principal members of the beta-thymosin family. The peptide was originally isolated from calf thymus and later found to be widely distributed in mammalian tissues and body fluids, including blood platelets, macrophages, spleen, liver, heart, and leukocytes. T β4 is a relatively small peptide with a molecular weight around 5 kDa. Its structure includes an acetylated N-terminus, a common feature in many naturally occurring peptides, which contributes to its stability and interaction with cellular targets.

In the body, T β4 serves as a major intracellular regulator of the actin cytoskeleton by binding monomeric globular actin (G-actin) and preventing its polymerization into filamentous actin (F-actin). This actin-sequestering function helps maintain a dynamic pool of G-actin available for rapid cytoskeletal remodeling, which is essential for cell migration, morphology, and motility. By controlling actin dynamics, T β4 influences a range of cellular processes including tissue development, cell movement, and maintenance of structural integrity.

Beyond its role in actin regulation, T β4 exhibits a spectrum of activities related to tissue repair and regeneration. Early research demonstrated that exogenous administration of T β4 facilitates wound healing by enhancing keratinocyte migration, promoting angiogenesis (formation of new blood vessels), and increasing collagen deposition in wound models. These activities contribute to accelerated wound closure and improved tissue remodeling in animal experiments, supporting the peptide’s therapeutic potential in skin repair. Preclinical studies have shown that T β4 can promote healing in full-thickness dermal wounds and has been investigated in clinical trials for chronic non-healing ulcers in humans, where it appeared to shorten healing time.

The regenerative properties of T β4 extend to several organ systems beyond the skin. In models of cardiac injury, systemic administration of T β4 promotes survival and migration of cardiac progenitor cells, stimulates coronary vessel growth, and reactivates embryonic gene programs associated with heart development, suggesting roles in myocardial repair and regeneration. Similar benefits have been observed in ischemic limb models and neural injury paradigms, where T β4 modulates inflammation, reduces apoptosis, and supports restoration of damaged tissues. T β4 has also been studied as an agent that may influence cellular responses to ischemic or oxidative stress and in models of neurorestoration following traumatic brain injury, wherein treatment reduced neuronal death and improved functional outcomes.

At the molecular level, T β4’s interaction with actin and other signaling pathways facilitates its effects on cell migration and differentiation. By enhancing angiogenic responses and modulating inflammatory mediators, the peptide contributes to an improved microenvironment for tissue repair. These actions have made it a candidate for research into novel therapies aimed at accelerating healing in conditions such as corneal injuries, dermal ulcers, myocardial infarction, and neurological damage, though the precise mechanisms and clinical efficacy continue to be actively investigated.

Despite promising findings in experimental models and early human studies, T β4 is not yet widely approved for general therapeutic use, and its clinical application remains the subject of ongoing research. Its diverse biological functions and the breadth of tissues in which it is expressed underscore its importance as a multifunctional peptide with significant roles in cellular repair, regeneration, and adaptation to injury.

References

Goldstein AL, Hannappel E, Sosne G, Kleinman HK (2012) Thymosin β4: a multi-functional regenerative peptide. Expert Opinion on Biological Therapy 12(1) 37–51 DOI: 10.1517/14712598.2012.634793

Xiong Y, Zhang Y, Zhang ZG, et al. (2012) Neuroprotective and neurorestorative effects of thymosin beta4 treatment initiated 6 hours post injury following traumatic brain injury in rats. Journal of Neurosurgery 116(5) 1081–1092 DOI: 10.3171/2012.1.JNS111729