What is Thymosin Alpha-1?
Our molecular records give thymosin alpha-1 as CAS 62304-98-7, formula C129H215N33O55, average molecular weight 3108.29, with the synonyms thymalfasin and T-alpha-1. No residue listing is carried, so the sequence is not reproduced here. The natural form is an acetylated peptide released by processing of the precursor protein prothymosin alpha.
The recorded formula contains no sulfur, which rules out the methionine and cysteine oxidation chemistry that governs stability planning for many peptides this size. What governs it instead is the strongly acidic character reported for this molecule, its high proportion of charged residues and the absence of a stable fold, all of which make it very water soluble and largely unstructured until it meets a binding partner or a membrane.
In the literature the peptide is studied as a modulator of innate and adaptive immune signalling. Cell work reports engagement of Toll-like receptors 2 and 9 on dendritic cells and monocytes, with effects on dendritic cell maturation, cytokine profiles and T cell differentiation, and animal studies have used it in infection and immunosuppression models. No single high-affinity receptor has been established, its activity is described as context-dependent rather than uniformly stimulatory, and the relationship between free peptide and precursor in living tissue is unresolved.
Reconstitution & handling
Sterile or bacteriostatic water dissolves the cake readily given the charge profile. Add the diluent against the vial wall and swirl gently until clear rather than shaking. Concentration is the labelled mass divided by the diluent volume, with net peptide content applied where an accurate molar figure is required.
Storage & stability
Keep the sealed lyophilized vial at -20 °C, desiccated and shielded from light. With no sulfur in the recorded formula, oxidation is a lesser concern than the slow hydrolytic changes, deamidation among them, that run faster at higher pH. Reconstituted material should be aliquoted for single use, held at 2 to 8 °C, and not left standing in alkaline buffer.
How it's tested
Purity is measured by reversed-phase HPLC at 214 and 220 nm, since ultraviolet absorbance above 250 nm is weak for this molecule. Identity is confirmed by mass spectrometry against the theoretical average mass of 3108.29, including the amino-terminal acetylation that defines the natural form. Net peptide content, water and residual counterion are reported, and a lot-matched certificate of analysis is available on request.