ATX-GD-59 (5D-K1 Component) | CAS 1650595-97-3 (Component Peptide) | Tolerogenic Peptide (Research Use Only) | Knowlux

Product Description

ATX-GD-59 is a synthetic peptide-based immunotherapeutic candidate developed for antigen-specific tolerance induction in Graves' disease, supplied by Knowlux for laboratory research use. The material described here corresponds to the 5D-K1 component peptide of the ATX-GD-59 mixture, a 21-residue sequence derived from the thyrotropin receptor (TSHR) with charged N- and C-terminal flanking residues added to improve solubility. The sequence is H-Lys-Lys-Lys-Lys-Tyr-Val-Ser-Ile-Asp-Val-Thr-Leu-Gln-Gln-Leu-Glu-Ser-His-Lys-Lys-Lys-OH, corresponding to the one-letter code KKKKYVSIDVTLQQLESHKKK. The molecular formula is C114H198N32O32 and the formula weight is 2529.26 g/mol. Each lot is released with a lot-specific COA, MSDS and analytical traceability.

CAS and Product Identity Clarification: ATX-GD-59 is not a single molecular entity. Published and sponsor documentation describe it as a lyophilized equimolar mixture of two synthetic peptides derived from the TSHR sequence: a 15-residue peptide (9B-N) matching an exact TSHR segment, and a 21-residue peptide (5D-K1) bearing charged flanking residues for solubility. Because ATX-GD-59 is a defined mixture rather than a single covalently defined molecule, it does not carry a single unified CAS registry; commercial listings for ATX-GD-59 frequently show the CAS field as N/A or 000-00-0. The CAS 1650595-97-3 is assigned to the 5D-K1 component peptide and is the appropriate registry for the single-peptide material described in this specification. The molecular formula C114H198N32O32 and molecular weight 2529.26 are consistent with the 5D-K1 component and are the values adopted throughout this document. Knowlux declares which component or mixture is supplied, and its stoichiometry if applicable, on the lot COA. Buyers should confirm whether the quoted material is the 5D-K1 single peptide (CAS 1650595-97-3) or the two-peptide ATX-GD-59 mixture before procurement.

Structural and Mechanistic Note: The 5D-K1 peptide is designed to bind directly to MHC class II molecules without prior antigen processing, a property conferred by its short length. In the ATX-GD-59 therapeutic concept, presentation of the peptide on resting dendritic cells is intended to switch off rather than activate TSHR-reactive CD4+ T cells, thereby reducing the production of stimulating anti-TSHR antibodies that drive Graves' hyperthyroidism. The peptide is linear, contains no cysteine or disulfide bonds, and has free N- and C-termini. It contains no methionine or tryptophan; the sole aromatic residue is Tyr5. The four N-terminal and three C-terminal lysine residues provide the charged flanks that distinguish 5D-K1 from the exact TSHR sequence and improve aqueous handling.

Product Parameters

Product Details

1. Overview and Clinical Context

ATX-GD-59 is an investigational antigen-specific immunotherapeutic for Graves' disease. It was designed on the principle that short TSHR-derived peptides can load directly onto MHC class II on resting dendritic cells and, upon repeated dosing, induce tolerance to the receptor rather than generalized immunosuppression. The clinical evidence base is limited: a single open-label, uncontrolled Phase 1 study in twelve participants has been reported, with free thyroid hormone normalization observed in a subset of completers and injection-site reactions dominating the adverse-event profile. A successor Phase 2 program is registered as suspended due to recruitment difficulties. No binding affinity, T-cell activation potency, or pharmacokinetic data have been published for ATX-GD-59 or its component peptides. The material supplied under this specification is research-grade and is not intended for human administration; the clinical context is provided solely to explain the compound's research interest.

2. Research Applications

Documented or reasonably inferred research applications for the 5D-K1 peptide and the ATX-GD-59 mixture include:

• MHC class II binding and antigen presentation studies using TSHR-derived peptides

• CD4+ T-cell tolerance induction and regulatory T-cell mechanism research

• Graves' disease and TSHR autoantibody pathophysiology models

• Peptide-based antigen-specific immunotherapy development

• Autoimmune thyroid disease biomarker and translational research

• Reference standard development for HPLC and LC-MS analytical methods

These descriptions are derived from published research and sponsor documentation and are provided for scientific reference only.

Quality Control

Solubility and Handling

Solubility: Numeric solubility data for the 5D-K1 peptide are not published in the sourced literature. Supplier listings declare solubility as H2O/DMSO without a concentration limit. Given the peptide's four N-terminal and three C-terminal lysine residues, it is expected to be highly hydrophilic and to dissolve readily in aqueous media; the charged flanks were introduced specifically to improve solubility relative to the exact TSHR sequence. DMSO is a viable alternative for stock preparation where an organic vehicle is required. Working concentration should be established empirically on the specific lot and buffer system.

Handling Precautions: Use powder-handling containment (glove box or fume hood with particulate control). Avoid inhalation of fine powder. Wear nitrile gloves, lab coat, and eye protection. The peptide contains no cysteine, methionine, or tryptophan, so reducing agents and oxidation-protection measures are not required. The lyophilized powder is hygroscopic; equilibrate vials to room temperature before opening.

Storage and Stability

Documentation Support

Per lot: COA, MSDS, HPLC chromatogram, and mass spectrometry data. Component identity (5D-K1 single peptide versus ATX-GD-59 two-peptide mixture), acetate content, water content, peptide content, and endotoxin data available on request. Custom specifications and third-party inspection can be arranged on a project basis.

About Knowlux

Knowlux Biotechnology is a GMP-oriented manufacturer and supplier of peptides, APIs and fine-chemical research compounds, operating from Hubei, China. We serve research groups, CDMOs and distributors in more than 40 countries, and support contract synthesis, custom packaging and technical documentation requests.

Compliance Statement

FOR RESEARCH USE ONLY. NOT FOR HUMAN USE. NOT FOR DIAGNOSTIC OR THERAPEUTIC USE.

This product is supplied for laboratory research use only. It is not for human or animal administration, not for diagnostic or therapeutic use, not for retail sale, and not for personal use. ATX-GD-59 and its 5D-K1 component have been investigated in a Phase 1 clinical study for Graves' disease but are not approved as medicinal products in any jurisdiction; the material offered under this specification is research-grade and is not intended for clinical use. The purchaser is responsible for verifying product specifications against their specific research requirements and for compliance with all applicable institutional, local, and national regulations governing research chemical acquisition, storage, and use. Research context statements are for scientific reference only and do not constitute medical advice, promotional claims, or dosing guidance.

Data Verification Notes

The 5D-K1 sequence KKKKYVSIDVTLQQLESHKKK and the corresponding three-letter sequence are confirmed by NCATS Inxight Drugs (UNII 348Q6LU5A5, CAS 1650595-97-3) and by multiple supplier listings. The molecular formula C114H198N32O32 and molecular weight 2529.26 are confirmed by the supplier technical specifications and are consistent with the 5D-K1 sequence. The characterization of ATX-GD-59 as an equimolar mixture of a 15-residue peptide (9B-N) and a 21-residue peptide (5D-K1) is from the scientific literature and patent-adjacent descriptions; the absence of a single unified CAS for the mixture is corroborated by multiple catalogue listings showing CAS N/A. The clinical evidence summary (single open-label Phase 1, n=12; suspended Phase 2) is from the scientific wiki synthesis and is consistent with the registered trial descriptions. No binding affinity, T-cell potency, or pharmacokinetic constants are adopted because none were identified in the sourced data; this absence is explicitly noted rather than inferred around. The quality specifications are from the supplier technical sheets and are reported as-is. Solubility is reported as the supplier-declared H2O/DMSO without a numeric limit, and the absence of a published numeric value is stated rather than filled with an assumed figure.

Formatting Note: All formulas, sequences, and comparison operators use plain ASCII notation to prevent character corruption on the platform. Section headings, table alignment, and spacing follow the approved product detail pattern. No trailing spaces or non-breaking characters are used; tables use consistent pipe alignment. No web links or hyperlinks are included in this document.