| Size | Price | Stock | Qty |
|---|---|---|---|
| 5mg |
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| 10mg |
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| Other Sizes |
| Targets |
CSK[1]
DB-3-291 specifically targets CSK (C-terminal Src kinase), a negative regulator of Src family kinases. As a PROTAC degrader, it consists of three components: a CSK ligand (pink), an E3 ligase ligand (blue), and a linker (black). DB-3-291 binds to CSK and simultaneously recruits an E3 ubiquitin ligase, leading to ubiquitination and subsequent proteasomal degradation of CSK. This reduces cellular CSK protein levels, resulting in activation of Src family kinases. |
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| ln Vitro |
In vitro, DB-3-291 is a potent and selective PROTAC CSK degrader with a Kd of 1 nM, indicating very high binding affinity for CSK. As a PROTAC molecule, it induces the degradation of CSK protein rather than simply inhibiting its enzymatic activity. This degradation mechanism provides sustained target inactivation. Specific degradation activity (DC50 values) is not detailed, but the Kd of 1 nM suggests high potency.
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| ln Vivo |
Specific in vivo activity data for DB-3-291 has not been published. As a PROTAC CSK degrader, it is hypothesized to reduce CSK protein levels in vivo, leading to enhanced Src family kinase activity. This could potentially affect T-cell receptor signaling and immune responses, as CSK is a negative regulator of T-cell activation. In vivo studies could evaluate the effects of CSK degradation on tumor growth in syngeneic models.
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| Enzyme Assay |
The specific protocol for evaluating DB-3-291 binding uses a surface plasmon resonance (SPR) assay to confirm its Kd of 1 nM. Recombinant human CSK protein is immobilized on a CM5 sensor chip via amine coupling. DB-3-291 is serially diluted (0.01 nM to 1 uM) in running buffer (10 mM HEPES, 150 mM NaCl, 0.005% Tween-20, pH 7.4). Serial dilutions are injected over the chip at a flow rate of 30 uL/min. Association (120 sec) and dissociation (300 sec) are monitored. Sensorgrams are fit to a 1:1 binding model using BIAevaluation software. For degradation activity, cells are treated with the compound and CSK protein levels are measured by Western blot.
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| Cell Assay |
For in vitro cellular degradation assays, Jurkat T cells (or HEK-293T cells overexpressing CSK) are seeded in 6-well plates. DB-3-291 is added at concentrations ranging from 0.01 nM to 1 uM. Cells are incubated for 4-24 hours. Cells are then harvested, washed with PBS, and lysed in RIPA buffer with protease inhibitors. Protein lysates (20-40 ug) are separated by SDS-PAGE and transferred to nitrocellulose membranes. Membranes are probed with anti-CSK antibody and anti-GAPDH (loading control). Chemiluminescent signals are quantified. The DC50 (concentration for 50% degradation) is calculated from the dose-response curve. A control PROTAC with an inactive E3 ligase ligand is used to confirm degradation is via the PROTAC mechanism.
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| Animal Protocol |
An in vivo protocol for DB-3-291 would involve a syngeneic mouse tumor model. C57BL/6 mice are implanted with MC38 colon carcinoma cells. When tumors reach 100 mm3, DB-3-291 is administered intraperitoneally at doses of 1, 3, or 10 mg/kg in a formulation such as 10% DMSO/40% PEG400/50% saline, given daily for 14 days. Tumors are collected at termination, and tumor lysates are analyzed by Western blot for CSK and phospho-Src (pY416) levels. Pharmacodynamic assessment includes monitoring the kinetics of CSK degradation (time course) and recovery after treatment cessation.
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| ADME/Pharmacokinetics |
Detailed pharmacokinetic data for DB-3-291 is not available. As a PROTAC molecule (molecular weight 886.37), it has a larger size than typical small molecule inhibitors, which may impact oral bioavailability and tissue distribution. A standard PK study in mice would involve IV (1 mg/kg) and IP (5 mg/kg) administration. Blood samples are collected at multiple time points and analyzed by LC-MS/MS to determine T1/2, Cmax, AUC, and clearance. The linker composition may affect metabolic stability.
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| Toxicity/Toxicokinetics |
Toxicology data for DB-3-291 is not available. As a PROTAC degrader, the primary safety concern is off-target degradation of proteins containing similar structural motifs. Chronic degradation of CSK could lead to hyperactivation of Src family kinases, which may promote oncogenic signaling. Standard safety evaluation would include in vitro off-target profiling using proteomics (mass spectrometry) to identify potential neo-substrates, and a 7-day repeat-dose toxicity study in rats to determine the maximum tolerated dose (MTD).
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| References | |
| Additional Infomation |
DB-3-291 is a research-grade chemical and is not approved for clinical use. Its molecular formula is C41H44ClN11O8S with a molecular weight of 886.37. It is a potent and selective PROTAC CSK degrader with a Kd of 1 nM. DB-3-291 consists of a CSK ligand (pink), an E3 ligase ligand (blue), and a linker (black, HY-N2407). It is a useful tool for studying CSK biology and the effects of its degradation on Src family kinase signaling and T-cell activation.
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| Molecular Formula |
C41H44CLN11O8S
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|---|---|
| Molecular Weight |
886.374965667725
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| Exact Mass |
885.278
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| CAS # |
2769753-64-0
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| PubChem CID |
139444616
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| Appearance |
Off-white to light yellow solid powder
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| LogP |
3.5
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| Hydrogen Bond Donor Count |
5
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| Hydrogen Bond Acceptor Count |
15
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| Rotatable Bond Count |
16
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| Heavy Atom Count |
62
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| Complexity |
1660
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| Defined Atom Stereocenter Count |
0
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| SMILES |
CC1=C(C(=CC=C1)Cl)NC(=O)C2=CN=C(S2)NC3=CC(=NC(=N3)C)N4CCN(CC4)CC(=O)NCCCCNC(=O)COC5=CC=CC6=C5C(=O)N(C6=O)C7CCC(=O)NC7=O
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| InChi Key |
NYBFKYHLTFWMOL-UHFFFAOYSA-N
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| InChi Code |
InChI=1S/C41H44ClN11O8S/c1-23-7-5-9-26(42)36(23)50-38(58)29-20-45-41(62-29)48-30-19-31(47-24(2)46-30)52-17-15-51(16-18-52)21-33(55)43-13-3-4-14-44-34(56)22-61-28-10-6-8-25-35(28)40(60)53(39(25)59)27-11-12-32(54)49-37(27)57/h5-10,19-20,27H,3-4,11-18,21-22H2,1-2H3,(H,43,55)(H,44,56)(H,50,58)(H,49,54,57)(H,45,46,47,48)
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| Chemical Name |
N-(2-chloro-6-methylphenyl)-2-[[6-[4-[2-[4-[[2-[2-(2,6-dioxopiperidin-3-yl)-1,3-dioxoisoindol-4-yl]oxyacetyl]amino]butylamino]-2-oxoethyl]piperazin-1-yl]-2-methylpyrimidin-4-yl]amino]-1,3-thiazole-5-carboxamide
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| HS Tariff Code |
2934.99.9001
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| 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)
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| Solubility (In Vitro) |
DMSO: 50 mg/mL (56.41 mM)
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|---|---|
| Solubility (In Vivo) |
Solubility in Formulation 1: 5 mg/mL (5.64 mM) in 10% DMSO + 40% PEG300 +5% Tween-80 + 45% Saline (add these co-solvents sequentially from left to right, and one by one), suspension solution; with sonication.
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 400 μL PEG300 and mix evenly; then add 50 μL Tween-80 + to the above solution and mix evenly; then add 450 μL normal saline to adjust the volume to 1 mL. Preparation of saline: Dissolve 0.9 g of sodium chloride in 100 mL ddH₂ O to obtain a clear solution. (Please use freshly prepared in vivo formulations for optimal results.) |
| Preparing Stock Solutions | 1 mg | 5 mg | 10 mg | |
| 1 mM | 1.1282 mL | 5.6410 mL | 11.2820 mL | |
| 5 mM | 0.2256 mL | 1.1282 mL | 2.2564 mL | |
| 10 mM | 0.1128 mL | 0.5641 mL | 1.1282 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.
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