TB-500 vs Thymosin Alpha-1
Side-by-side literature comparison of two thymic-derived research peptides that share a naming lineage but engage entirely different molecular pathways in the published literature.
Side-by-Side Attributes
Objective data pulled from the published peptide literature. For research context only — not efficacy or performance claims.
| Attribute | TB-500 | Thymosin Alpha-1 |
|---|---|---|
| Class | Thymosin Beta-4 fragment | Thymosin Alpha peptide |
| Length | Typically 17-mer (or 4-mer LKKTETQ) | 28 amino acids |
| Molecular Weight | ~889 Da (LKKTETQ fragment) / ~4963 Da (full TB-4) | ~3108 Da |
| Sequence family lineage | β-thymosin (Beta) family | α-thymosin (Alpha) family — genetically & structurally unrelated to β-family |
| N-terminal modification | Free amine (fragment); acetylated in full TB-4 | N-acetylated |
| Primary literature target | G-actin sequestration (binds monomeric actin ~1:1) | TLR-dependent immune-signalling pathways |
| Origin protein | Thymosin Beta-4 (β-thymosin family) | Preproprotein prothymosin α (α-thymosin family) |
| First described | TB-4 by Goldstein et al., ~1981 | TA-1 by Goldstein et al., ~1977 |
| Synthesis complexity | Straightforward Fmoc SPPS for the 17-mer fragment | SPPS with on-resin N-acetylation |
| Endotoxin release spec (BioInfinity) | < 0.5 EU/mg by LAL | < 0.5 EU/mg by LAL |
| Third-party COA lab (BioInfinity) | Verum Analytics, Switzerland | Verum Analytics, Switzerland |
Literature Context
TB-500 and Thymosin Alpha-1 share the word "thymosin" in their names but belong to two entirely different peptide families that were named separately in the 1970s–1980s thymic-peptide research corpus. The alpha (α) and beta (β) thymosins are genetically distinct, structurally unrelated, and engage completely different molecular pathways.
TB-500 is a fragment of Thymosin Beta-4, the most abundant intracellular actin-sequestering protein in mammalian cells. Its primary literature target is G-actin — TB-4 binds monomeric actin at approximately 1:1 stoichiometry and modulates actin-cytoskeleton dynamics. Thymosin Alpha-1, by contrast, is investigated in the immune-signalling literature, particularly around TLR-dependent dendritic-cell maturation, cytokine modulation (IL-2, IFN-γ), and T-cell differentiation preclinical models.
From a synthesis standpoint TA-1 is the more complex peptide of the two — it's longer (28-mer vs the 17-mer TB-500 fragment) and requires N-terminal acetylation, so the standard SPPS workflow adds an on-resin acetylation step. Both are supplied by BioInfinity strictly for laboratory research; neither is FDA-approved under BioInfinity supply.
Research Contexts in the Literature
Overlapping
- General thymic-peptide biology reference
- Peptide-fragment structure-activity literature
- Standard SPPS synthesis & QC workflows
TB-500 only
- G-actin sequestration stoichiometry assays
- Actin-cytoskeleton dynamics research
- Endothelial cell migration models
- Cardiomyocyte proliferation preclinical models
- Corneal epithelial repair models
- Angiogenesis / tube-formation in-vitro
Thymosin Alpha-1 only
- TLR-signalling pathway in-vitro studies
- Dendritic-cell maturation preclinical models
- T-cell differentiation & Th1/Th2 balance research
- Cytokine (IL-2, IFN-γ) modulation assays
- Antiviral-response preclinical model literature
- Immune-checkpoint pathway research
All products supplied by BioInfinity are for in-vitro laboratory research use only. Not FDA-approved. Not intended for human or veterinary use. This page is a literature summary — not medical, dosing, or usage guidance.