Thymogen is the dipeptide L-glutamyl-L-tryptophan (Glu-Trp, single-letter code EW), a synthetic peptide developed from studies of calf thymus extracts and known by the international non-proprietary name oglufanide. With two residues and a molecular weight of 333 g/mol it is one of the smallest peptides in the research range, and it is used in cell-based studies of innate immune signalling, cytokine expression and dipeptide transport. NuVion supplies Thymogen as a laboratory chemical for in vitro research use only.
Key facts
| Type | Synthetic dipeptide |
| Amino acid count | 2 |
| Sequence | L-Glu-L-Trp (alpha-linked) |
| Molecular formula | C16H19N3O5 (free dipeptide) |
| Molecular weight | 333.34 g/mol (free dipeptide) |
| CAS number | 38101-59-6 |
| Synonyms | Oglufanide, Glu-Trp, EW dipeptide, glutamyl-tryptophan |
| Supplied form | Lyophilised powder in a sealed vial |
Thymogen
$109 AUD
View productResearch use only. Not for human or veterinary use.
Structure and chemistry
Thymogen is the simplest possible peptide: two amino acids joined by a single amide bond. The bond runs from the alpha-carboxyl of glutamic acid to the alpha-amino group of tryptophan, which leaves the glutamate side-chain carboxyl, the tryptophan C-terminal carboxyl and the N-terminal amine all free. At neutral pH the molecule carries two negative charges and one positive charge, so it is an acidic, zwitterionic dipeptide with a net charge of minus one, and it dissolves readily in water. The free acid gives a mildly acidic solution; sodium salts of the dipeptide are also described, and oglufanide disodium is the form used in some published cell work.
The linkage isomer matters. Glutamic acid can form a peptide bond through its side-chain gamma-carboxyl instead of its alpha-carboxyl, and gamma-Glu-Trp is a different compound with different behaviour toward peptidases. A related research compound, golotimod (SCV-07), is gamma-D-glutamyl-L-tryptophan and should not be confused with Thymogen, which is the alpha-linked L,L dipeptide. Both stereocentres in Thymogen are in the natural L configuration.
Two features of the structure govern stability and detection. The tryptophan indole absorbs at 280 nm and fluoresces near 350 nm when excited at 280 nm, which gives a convenient handle for HPLC detection and for quantification, but it is also susceptible to oxidation and photodegradation, so solutions are protected from light. The N-terminal glutamate can cyclise slowly to pyroglutamate, particularly on heating or at low pH, giving a neutral-loss impurity that separates from the parent peak on RP-HPLC. As a dipeptide with a free N-terminus, Thymogen is a substrate for cytosolic and membrane-bound dipeptidases and is hydrolysed to free glutamate and tryptophan in serum-containing medium within hours, which sets the practical exposure window in cell experiments.
Mechanism of action
No dedicated receptor for Glu-Trp has been identified, and the mechanism is described at the level of the cellular responses that have been measured. In the THP-1 monocytic cell line, Glu-Trp has been reported to increase transcript levels of the endosomal Toll-like receptors TLR3, TLR7, TLR8 and TLR9, the cytosolic RNA sensors RIG-I and MDA5, and the downstream signalling components NF-kappaB1 and MAVS, with a corresponding increase in secretion of TNF-alpha and IL-1beta. The pattern is consistent with priming of pattern-recognition receptor pathways, without evidence of direct receptor agonism, and the effect is measured over hours by qPCR and ELISA.
The group that developed the compound has proposed that very short peptides, including Glu-Trp, can enter the nucleus and interact with DNA at specific sequences in promoter regions, altering transcription of genes for heat shock proteins, cytokines and cell cycle regulators. This model rests on molecular modelling and on in vitro binding and gene expression data, and it remains a hypothesis, with no established pathway behind it. The disodium salt, studied as oglufanide, has separately been reported to reduce endothelial cell proliferation and tube formation in culture and to lower VEGF and basic FGF output from cultured cells, which is the basis for its use in angiogenesis assays. As a dipeptide, Glu-Trp also falls within the substrate range of the proton-coupled peptide transporters PEPT1 and PEPT2, so its uptake into epithelial cells is transporter-mediated and can be blocked by competing dipeptides such as Gly-Sar.
Research applications
- Innate immune signalling studies in monocytic and macrophage cell lines: TLR and RIG-I-like receptor expression by qPCR, NF-kappaB reporter assays, and TNF-alpha and IL-1beta secretion by ELISA.
- Endothelial cell proliferation, migration and tube-formation assays, with VEGF and FGF2 measured in conditioned medium.
- Dipeptide transport experiments in Caco-2 or PEPT1-transfected cells, including competition with Gly-Sar and pH-dependence of uptake.
- Peptidase stability assays in serum, cell lysate or purified dipeptidase preparations, following loss of the parent by LC-MS.
- Structure-activity comparisons between alpha-Glu-Trp, gamma-Glu-Trp and D-amino acid analogues.
- Reference standard for RP-HPLC and LC-MS methods for short acidic peptides, using tryptophan absorbance or fluorescence for detection.
Thymogen sits in NuVion’s Immune Signalling category alongside other thymus-derived peptides.
Handling in the laboratory
Thymogen is supplied lyophilised and is reconstituted with bacteriostatic water added slowly to the vial and swirled until dissolved; the dipeptide is highly water-soluble and dissolves without difficulty. The reconstitution calculator converts vial content and diluent volume into a stock concentration. Because the free acid lowers the pH of unbuffered water, stocks intended for cell work are diluted into buffered medium or adjusted to neutral pH before use, and a vehicle control accounts for the benzyl alcohol carried over from the diluent.
Unopened vials are kept sealed, dry, away from light and refrigerated as stated on the product documentation. Reconstituted solution is refrigerated, protected from light and used within the period given on the documentation; for longer holding it is aliquoted and frozen, avoiding repeated freeze-thaw cycles. Light protection matters more for this compound than for most peptides because of the tryptophan. The compound is characterised by RP-HPLC for purity and by mass spectrometry for identity, and its small size means the parent ion at m/z 334 is easily resolved from pyroglutamate and free amino acid impurities.
Testing and supply from NuVion
NuVion’s Thymogen is manufactured at a GMP-audited facility and independently tested by Janoshik Analytical, with purity determined by RP-HPLC and identity confirmed by mass spectrometry. Most batches are tested, and the Certificate of Analysis for a tested batch is published on the product page and in the COA library. The peptide is supplied lyophilised in sealed vials and dispatched from within Australia.
Related compounds
Other thymus-derived and innate signalling peptides in the same category include thymulin, a zinc-dependent nonapeptide, and thymosin alpha-1, a 28-residue acetylated peptide studied in TLR signalling and dendritic cell models.
Frequently asked questions
What is Thymogen used for in research?
It is used as a defined dipeptide stimulus in cell-based assays of pattern-recognition receptor expression and cytokine secretion, in angiogenesis assays with endothelial cells, and in peptide transport and peptidase stability experiments. Its small size also makes it a convenient reference compound for analytical method development.
Is Thymogen the same as oglufanide?
Yes. Oglufanide is the international non-proprietary name for L-glutamyl-L-tryptophan, and Thymogen is the name under which the same alpha-linked dipeptide was originally described. Oglufanide disodium is the disodium salt of the same molecule. Gamma-linked and D-amino acid variants such as golotimod are different compounds.
Is Thymogen a therapeutic good in Australia?
No. NuVion’s Thymogen is a laboratory chemical for in vitro research. It is not included in the Australian Register of Therapeutic Goods, has not been assessed by the Therapeutic Goods Administration, and is not for human or veterinary use.
How should Thymogen be stored?
Lyophilised vials are kept sealed, dry, protected from light and refrigerated per the product documentation. Reconstituted solution is refrigerated, kept in the dark and used within the stated period, or aliquoted and frozen. Solutions are not heated, to limit pyroglutamate formation at the N-terminus.
Research use only. This product is a laboratory chemical supplied for in vitro research. It is not included in the Australian Register of Therapeutic Goods and has not been assessed by the Therapeutic Goods Administration for quality, safety or efficacy. It is not for human or veterinary use, and nothing on this page is a representation about therapeutic use.
