Thymosin Alpha-1 5mg

What Thymosin Alpha-1 is

Thymosin alpha-1 is a 28-residue linear peptide, acetylated at the N-terminus, with the 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. It corresponds to the N-terminal 28 residues of prothymosin alpha, was first isolated from thymus tissue and is now made by solid-phase synthesis. The acetyl cap is part of the definition rather than an optional extra, and with no cysteine in the chain there is no disulfide.

Despite the shared word, thymosin alpha-1 is unrelated to thymosin beta-4 and to the TB-500 fragment drawn from it. The two differ in length, sequence and structure and were grouped only because they came out of the same tissue extract. “Thymosin” on its own is therefore not an adequate identifier; a record needs the full name and the sequence.

Thymosin Alpha-1 5mg specification

How Thymosin Alpha-1 is analyzed

Count the side chains and the character of this peptide becomes clear: aspartate and glutamate fill nine of the 28 positions against four lysines, and the acetyl group removes the N-terminal positive charge, so the molecule is strongly acidic and more polar than its length suggests. It retains less on C18 than a typical 28-mer, so a method borrowed from hydrophobic peptides of similar size may need a shallower gradient from lower organic strength, and a wide-pore phase generally resolves a chain this long better than the pore sizes used for short sequences. There is no tryptophan, tyrosine or phenylalanine, which leaves 214 nm as the only sensible detection wavelength.

Two impurity classes stand out. Non-acetylated material is 42 Da lighter, carries an extra positive charge and is distinguished by mass spectrometry; deletion sequences, which accumulate over 28 coupling steps, differ from the target by a single residue and elute near the main peak. Thymosin Alpha-1 5mg has an independent HPLC result posted here; its vials have no lot marking, and a Thymosin Alpha-1 vial is linked to that result through crimp and cap color.

Research contexts for Thymosin Alpha-1

• Toll-like receptor signaling assays in lymphocyte-derived and dendritic cell cultures
• Method development for acidic, mid-length peptides on wide-pore reverse-phase columns
• Mass-spectrometric discrimination of acetylated and free-amine forms
• Deletion-sequence profiling in 28-residue solid-phase syntheses
• Nomenclature and identity work across the alpha and beta thymosin families

Thymosin Alpha-1 is stocked for receptor-signaling assays and analytical method work in vitro; it has no role outside the laboratory, human or animal.

Thymosin Alpha-1 questions

Is Thymosin Alpha-1 related to TB-500?

No. TB-500 derives from thymosin beta-4, an unrelated protein; the two share a historical name, not a sequence.

Why does the N-terminal acetyl group matter analytically?

It adds 42 Da and removes the N-terminal positive charge, shifting both mass and retention. Material that lacks it is a distinct impurity that a mass spectrum can separate from the target.

Why does a 28-residue peptide retain so weakly on C18?

Nine of its residues are aspartate or glutamate, making it far more polar than a typical peptide of the same length, so it releases at lower organic strength than chain length alone would predict.