| Size | Price | Stock | Qty |
|---|---|---|---|
| 5mg |
|
||
| 10mg |
|
||
| Other Sizes |
| Targets |
Cleavable Linker
Fmoc-Gly-Gly-D-Phe-OtBu does not target a specific biological receptor. It functions as a cleavable linker in ADCs. The Fmoc group protects the N-terminus during synthesis. The D-Phe residue may enhance stability toward proteolytic degradation. The linker is designed to be cleaved by specific proteases (e.g., cathepsin B) in the lysosomal compartment of target cells, releasing the attached payload. There is no direct biological activity; activity resides in the full ADC. |
|---|---|
| ln Vitro |
No independent in vitro biological activity is attributed to the linker itself; it is inactive without a conjugated payload. In the context of an ADC, the Fmoc-Gly-Gly-D-Phe-OtBu linker connects the antibody to a cytotoxic drug. In vitro cytotoxicity assays with ADCs containing this linker demonstrate target-dependent killing of cancer cells, with IC50 values in the low nanomolar to picomolar range depending on the payload and target expression level.
|
| ln Vivo |
In vivo studies are not performed with the linker alone. ADCs constructed using Fmoc-Gly-Gly-D-Phe-OtBu-based linkers have demonstrated in vivo efficacy in xenograft tumor models, with dose-dependent tumor growth inhibition and improved survival compared to control groups. The linker's stability in circulation (plasma) and efficient cleavage in the lysosome contribute to the therapeutic window of the ADC. The R-isomer may have different properties from the L-isomer.
|
| Enzyme Assay |
Cell-free enzymatic cleavage assays: Incubate the Fmoc-Gly-Gly-D-Phe-OtBu linker conjugated to a model payload with purified cathepsin B (1-10 U/mL) in acetate buffer (50 mM, pH 5.0, 1 mM EDTA, 5 mM DTT) for 1-24 hours at 37degC. Quench, extract, and analyze by HPLC or LC-MS to quantify release of the payload. For stability studies, incubate the linker-payload conjugate in human plasma (pH 7.4) at 37degC for up to 48 hours and measure intact conjugate by LC-MS. For Fmoc deprotection assays (synthesis validation), treat with 20% piperidine in DMF for 20 minutes at room temperature and analyze by HPLC to confirm removal of the Fmoc group.
|
| Cell Assay |
Not applicable for the linker alone as it lacks cytotoxic activity. For ADC studies, culture target antigen-positive and antigen-negative cancer cell lines in appropriate medium. Treat cells with ADCs synthesized using this linker (0.01-100 nM) for 72-96 hours. Assess cell viability by CellTiter-Glo or MTT. To study linker stability in cellular compartments, treat cells with fluorescently labeled ADC for 4-24 hours, fix, and image by confocal microscopy. Co-stain with LysoTracker and anti-payload antibody to monitor lysosomal trafficking and payload release. Perform competition assays by pre-incubating cells with excess unconjugated antibody to confirm target specificity.
|
| Animal Protocol |
Not applicable for the linker alone. For ADCs using this linker, in vivo efficacy studies are performed in xenograft mouse models. Inoculate target antigen-positive cancer cells subcutaneously in immunodeficient mice. When tumors reach ~100-150 mm3, administer the ADC via intravenous injection at doses of 1-10 mg/kg (based on antibody content), once weekly for 2-4 doses. Monitor tumor growth and body weight bi-weekly. At study endpoint, collect tumors for ex vivo IHC analysis (Ki-67, cleaved caspase-3). Assess linker stability in vivo by analyzing plasma samples at multiple time points post-dose using LC-MS to measure the intact ADC and released payload.
|
| ADME/Pharmacokinetics |
Pharmacokinetic properties are associated with the ADC, not the linker alone. The Fmoc-Gly-Gly-D-Phe-OtBu linker has a molecular weight of 557.64. As a protected peptide, it is not intended for in vivo use. The linker is soluble in DMSO (100 mg/mL, 179.33 mM). For storage, powder at -20degC; in solvent at -80degC (6 months) or -20degC (1 month), sealed, away from moisture. The tert-butyl ester (OtBu) group protects the C-terminus during peptide synthesis and is typically removed under acidic conditions (e.g., TFA) during linker activation or ADC synthesis.
|
| Toxicity/Toxicokinetics |
Fmoc-Gly-Gly-D-Phe-OtBu is a research chemical for in vitro use only. The linker itself is not administered in vivo, and no specific toxicity data are available. The compound is not intended for human consumption. As a peptide derivative, it is expected to have low acute toxicity. The D-isomer (D-Phe) may contribute to increased resistance to proteolytic degradation compared to L-isomers. Standard laboratory safety precautions (gloves, lab coat, safety glasses) should be used. Avoid inhalation, ingestion, and skin contact. Dispose of waste according to institutional guidelines. In case of accidental exposure, wash affected area with soap and water.
|
| References | |
| Additional Infomation |
Fmoc-Gly-Gly-D-Phe-OtBu is a cleavable ADC linker used in the synthesis of antibody-drug conjugates. It is the R-isomer of Fmoc-Gly-Gly-Phe-OtBu. The Fmoc (9-fluorenylmethoxycarbonyl) group is acid-labile and serves as a protecting group for the N-terminus during solid-phase peptide synthesis (SPPS). The Gly-Gly dipeptide provides flexibility, and the D-Phe residue may contribute to enhanced stability. The OtBu (tert-butyl ester) protects the C-terminal carboxyl group. The compound is exclusively for research use and not for diagnostic or therapeutic applications.
|
| Molecular Formula |
C32H35N3O6
|
|---|---|
| Molecular Weight |
557.64
|
| Related CAS # |
Fmoc-Gly-Gly-Phe-OtBu;236426-37-2
|
| Appearance |
White to off-white solid powder
|
| HS Tariff Code |
2934.99.9001
|
| Storage |
Powder -20°C 3 years 4°C 2 years In solvent -80°C 6 months -20°C 1 month Note: Please store this product in a sealed and protected environment (e.g. under nitrogen), avoid exposure to moisture. |
| Shipping Condition |
Room temperature (This product is stable at ambient temperature for a few days during ordinary shipping and time spent in Customs)
|
| Solubility (In Vitro) |
DMSO :~100 mg/mL (~179.33 mM)
|
|---|---|
| Solubility (In Vivo) |
Solubility in Formulation 1: ≥ 5 mg/mL (8.97 mM) (saturation unknown) in 10% DMSO + 90% Corn Oil (add these co-solvents sequentially from left to right, and one by one), clear solution.
For example, if 1 mL of working solution is to be prepared, you can add 100 μL of 50.0 mg/mL clear DMSO stock solution to 900 μL of corn oil and mix evenly. (Please use freshly prepared in vivo formulations for optimal results.) |
| Preparing Stock Solutions | 1 mg | 5 mg | 10 mg | |
| 1 mM | 1.7933 mL | 8.9664 mL | 17.9327 mL | |
| 5 mM | 0.3587 mL | 1.7933 mL | 3.5865 mL | |
| 10 mM | 0.1793 mL | 0.8966 mL | 1.7933 mL |
*Note: Please select an appropriate solvent for the preparation of stock solution based on your experiment needs. For most products, DMSO can be used for preparing stock solutions (e.g. 5 mM, 10 mM, or 20 mM concentration); some products with high aqueous solubility may be dissolved in water directly. Solubility information is available at the above Solubility Data section. Once the stock solution is prepared, aliquot it to routine usage volumes and store at -20°C or -80°C. Avoid repeated freeze and thaw cycles.
Calculation results
Working concentration： mg/mL；
Method for preparing DMSO stock solution： mg drug pre-dissolved in μL DMSO (stock solution concentration mg/mL). Please contact us first if the concentration exceeds the DMSO solubility of the batch of drug.
Method for preparing in vivo formulation:：Take μL DMSO stock solution, next add μL PEG300, mix and clarify, next addμL Tween 80, mix and clarify, next add μL ddH2O，mix and clarify.
(1) Please be sure that the solution is clear before the addition of next solvent. Dissolution methods like vortex, ultrasound or warming and heat may be used to aid dissolving.
(2) Be sure to add the solvent(s) in order.
Products are for research use only; We do not sell to patients
Copyright 2020 InvivoChem LLC | All Rights Reserved
