Description
Thymosin Alpha 1 (Tα1) is a naturally derived synthetic peptide studied in controlled laboratory environments for its activity in immune cell signaling models, particularly in the context of dendritic cell maturation, T-cell pathway modulation, and toll-like receptor (TLR) signaling research.
Chemical Information
- Chemical Name: Thymosin Alpha-1 (Tα1; thymalfasin; 28-amino acid thymic peptide)
- Also Known As: TA-1; Zadaxin (approved pharmaceutical form; not equivalent to research-grade compound); thymalfasin
- Discovery: First isolated from bovine thymus by Allan Goldstein’s laboratory in 1977 from Thymosin Fraction 5; identified as the N-terminal 28-amino acid fragment of the larger 109-amino acid precursor prothymosin alpha
- Compound Class: Endogenous thymic peptide; TLR2/TLR9 agonist on dendritic cells; immunomodulator (bidirectional calibration rather than pure immune stimulant)
- Sequence: Ac-Ser-Asp-Ala-Ala-Val-Asp-Thr-Ser-Ser-Glu-Ile-Thr-Thr-Lys-Asp-Leu-Lys-Glu-Lys-Lys-Glu-Val-Val-Glu-Glu-Ala-Glu-Asn-OH
- Molecular Formula: C129H215N33O55
- Molecular Weight: 3,108.3 g/mol
- CAS Number: 62304-98-7
- Structural features: N-terminally acetylated; net negative charge at physiological pH due to high aspartate/glutamate content; sensitive to agitation — vigorous shaking disrupts secondary structure
Applications
- TLR2 and TLR9 dual receptor activation research on dendritic cells. Thymosin Alpha-1 activates TLR2 on myeloid dendritic cells (mDCs) through NF-kB and p38 MAPK cascades, driving DC maturation with upregulation of CD80, CD86, and MHC class II surface markers. It simultaneously activates TLR9 on plasmacytoid dendritic cells (pDCs) through MyD88-IRF7 signaling, driving IFN-alpha production; the Romani et al. 2004 paper established TLR9/MyD88 as the primary signaling node for antifungal Th1 priming; the Tao et al. 2023 review documented TLR3, TLR4, TLR7, and TLR9 all as potential Thymosin Alpha-1 interaction points with distinct downstream cascades
- IDO-mediated tolerogenic pathway research. Thymosin Alpha-1 through TLR9 activation induces indoleamine 2,3-dioxygenase (IDO) expression in dendritic cells, generating a tolerogenic environment alongside Th1 priming. The Romani et al. 2006 paper characterized this dual Th1-activation/tolerance-calibration profile. Thymosin Alpha-1 primes DCs for Th1 immunity while simultaneously establishing regulatory T cell generation through IDO-mediated tryptophan catabolism; this bidirectional profile distinguishes it mechanistically from pure Th1 stimulants
- T-cell differentiation and maturation research. Downstream of TLR-activated DC maturation, Thymosin Alpha-1 promotes differentiation of naive T cell progenitors toward CD4+ helper and CD8+ cytotoxic lineages. Upregulation of CD3, CD4, and CD8 surface markers on thymocytes is documented in preclinical models. The research question of whether Thymosin Alpha-1 acts primarily on DC upstream activation or directly on T cell progenitors is an active area of investigation given the uncertainty about its precise primary receptor binding partner
- Thymosin Alpha-1 versus Thymalin comparative research. Thymosin Alpha-1 (28 AA; defined sequence) and Thymalin (polypeptide complex containing multiple active components including EW and KE dipeptides alongside larger polypeptide fractions) provide two levels of thymic bioregulator complexity. Thymosin Alpha-1 provides a precisely defined single-sequence reference point; Thymalin provides the full-complement polypeptide mix.
- Receptor interaction agitation sensitivity research. Thymosin Alpha-1 is specifically sensitive to agitation-mediated structural disruption; vigorous shaking degrades the peptide’s secondary structure and reduces biological activity. This physical handling sensitivity is itself a research variable for experiments examining how peptide secondary structure affects TLR2/TLR9 binding geometry and activation efficiency
Storage and Handling
Store lyophilized powder at -20C for long-term stability, or at 2-8C for short-term use. Protect from heat, light, and air exposure. Do not shake at any stage. Thymosin Alpha-1 is sensitive to agitation; swirl or roll gently only. Store reconstituted solutions at 2-8C and use promptly. Do not freeze reconstituted solution. Avoid repeated freeze-thaw cycles.
Compliance Notice
Thymosin Alpha-1 is for laboratory research use only. They are not for human or veterinary use and carry no therapeutic, diagnostic, or clinical indication. Note that thymalfasin (Zadaxin) is approved in 35+ countries for hepatitis B. However, this research-grade compound is not equivalent to the approved pharmaceutical formulation. FDA has not evaluated this product. By purchasing this product, the buyer confirms that they will follow appropriate institutional safety procedures and use it exclusively for controlled research.
