Thymosin Alpha-1 (TA-1) Testing
MW: 3108.32 g/molHalf-life: ~2 hoursStatus: Approved as Zadaxin in many countries
28-residue thymic peptide; immunomodulator approved for hepatitis B/C in some countries (Zadaxin).
Mechanism of action
28-residue thymic peptide that modulates T-cell development and function via Toll-like receptor signaling. Augments Th1 immune response; approved in >35 countries for chronic hepatitis B/C and as adjuvant to vaccines.
Sequence & structure
Ac-SDAAVDTSSEITTKDLKEKKEVVEEAEN (28 residues, N-acetylated)
N-terminal acetylation is essential — deacetylated forms have lower activity. Acidic peptide (pI ~4.2).
Research areas
- ●Chronic viral infection (HBV, HCV)
- ●Cancer immunotherapy adjuvant
- ●Sepsis (CASS trial)
- ●Vaccine response in elderly
What we test on Thymosin Alpha-1 (TA-1)
RP-HPLC, intact mass, N-acetyl confirmation by MS/MS, mandatory LAL endotoxin for injectable lots.
Standard Immune & Anti-Inflammatory Panel
- ✓RP-HPLC purity
- ✓ESI-MS identity
- ✓Endotoxin (LAL, USP <85>)
- ✓SEC for LL-37 aggregation
Common impurities & failure modes
- Deacetylated TA-1
−42 Da; reduced activity.
- Deamidation (Asn26)
Stability indicator.
- Truncation
Particularly at the C-terminal acidic stretch.
- Endotoxin
Immunomodulators must be endotoxin-free; LAL mandatory.
Regulatory status
Approved as Zadaxin in many countries (not FDA-approved in US).
Related Immune & Anti-Inflammatory peptides
KPV
342.43 g/mol
C-terminal tripeptide of α-MSH; anti-inflammatory.
LL-37 (Cathelicidin)
4493.33 g/mol
Only human cathelicidin antimicrobial peptide; broad-spectrum antimicrobial and immunomodulator.
Thymagen / Thymogen
333.34 g/mol
Synthetic dipeptide bioregulator based on natural thymic peptides.
Thymulin (FTS-Zn)
847.85 g/mol
Nonapeptide thymic hormone requiring zinc for activity.