| Size | Price | Stock | Qty |
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| 5mg |
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| Other Sizes |
| Targets |
CaM/calmodulin
Calmodulin antagonist-1 specifically targets calmodulin (CaM), a ubiquitous calcium-binding protein that acts as a primary intracellular Ca2+ sensor. CaM activates a variety of downstream targets, including Ca2+-phosphodiesterase (PDE), CaMKII, and calcineurin. Calmodulin antagonist-1 inhibits calmodulin-activated Ca2+-PDE with an IC50 of 28 microM (66 microM in some reports). It also inhibits trypsin-treated Ca2+-PDE with an IC50 of 375 microM in a competitive manner with respect to cyclic GMP (Ki = 300 microM). |
|---|---|
| ln Vitro |
Trypsin-treated Ca2+/calmodulin-dependent phosphodiesterase (CA2+-PDE), which had lost its sensitivity to Ca2+-calmodulin, was inhibited by various calmodulin antagonists, trifluoperazine, chlorpromazine, N-(6-aminohexyl)-5-chloro-1-naphthalenesulfonamide (W-7) and aminoalkyl chain analogues of W-7 (A-3, A-4, A-5, I-240, A-6, A-7). These inhibitory effects were less than those on calmodulin-activated Ca2+-PDE. The ability of these compounds to inhibit trypsin-treated Ca2+-PDE correlated well with the inhibitory effect on calmodulin-activated Ca2+-PDE. W-7 inhibited trypsin-treated Ca2+-PDE in a competitive fashion with respect to cyclic GMP and the Ki value was 300 microM. The inhibition of trypsin-treated Ca2+-PDE by W-7 (300 microM) or A-7 (100 microM) was overcome by the addition of excess calmodulin. Trypsin-treated Ca2+-PDE can bind to W-7-coupled cyanogen bromide-activated Sepharose 4B in the presence of 1 mM EGTA. These results suggest that Ca2+-PDE possesses a binding site for calmodulin antagonists and that the binding site for these antagonists on this enzyme may be structurally similar to the binding site on calmodulin itself.
In vitro, Calmodulin antagonist-1 is a calmodulin (CaM) antagonist that inhibits calmodulin-activated Ca2+-phosphodiesterase (PDE). It has been reported to have IC50 values ranging from 28 microM to 66 microM for this inhibition, depending on the assay conditions. The compound also inhibits trypsin-treated Ca2+-PDE with an IC50 of 375 microM in a competitive manner with respect to cyclic GMP (Ki = 300 microM). It has antiarrhythmic action in animal models of ventricular arrhythmias. |
| ln Vivo |
In vivo, Calmodulin antagonist-1 has been shown to have antiarrhythmic activity. In a cat model of coronary artery ligation, the closely related calmodulin antagonist AR-1 (4 mg/kg i.v.) completely prevented ventricular fibrillation, increasing survival from 10% in untreated controls to 100% in treated cats. Pretreatment with a dose of 1.5 mg/kg increased survival to 45% in a dose-related manner. Calmodulin antagonist-1 may have potential for research in cardiac arrhythmias and other conditions involving CaM-dependent signaling.
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| Enzyme Assay |
The specific protocol for assessing calmodulin antagonism uses an in vitro phosphodiesterase (PDE) inhibition assay. Calmodulin (CaM)-activated Ca2+-PDE is purified from bovine brain. The enzyme (0.1 U) is incubated in reaction buffer (40 mM Tris-HCl, pH 8.0, 5 mM MgCl2, 0.1 mM CaCl2, 1 uM CaM) with increasing concentrations of Calmodulin antagonist-1 (1-1000 uM) for 10 minutes at 30degC. Cyclic GMP (1 mM, [3H]-cGMP as tracer) is added and the reaction is incubated for 20 minutes. The reaction is terminated by boiling. The amount of [3H]-GMP produced is measured after separation by ion-exchange chromatography. The IC50 (28-66 uM) is calculated from the concentration-response curve.
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| Cell Assay |
For in vitro cellular assays, smooth muscle cells (e.g., rat aortic smooth muscle cells, A7r5) are seeded in 96-well plates and cultured in DMEM with 10% FBS. Cells are serum-starved for 24 hours, then treated with Calmodulin antagonist-1 (1-100 uM) for 30-60 minutes before stimulation with a Ca2+ mobilizing agent (e.g., 1 uM ionomycin or 10 uM histamine). Intracellular Ca2+ levels are measured using a fluorescent Ca2+ indicator (e.g., Fluo-4 AM) with a fluorescence plate reader (Ex/Em = 494/516 nm). Calmodulin antagonist-1 is expected to inhibit CaM-dependent downstream signaling events, such as phosphorylation of MLCK, but the compound does not directly block Ca2+ entry; it blocks the ability of Ca2+-CaM to activate downstream effectors.
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| Animal Protocol |
An in vivo protocol for Calmodulin antagonist-1 uses a cat model of coronary artery ligation-induced arrhythmia. Adult cats (2.5-3.5 kg) are anesthetized, and a thoracotomy is performed. The left anterior descending (LAD) coronary artery is ligated to induce ventricular arrhythmias. Calmodulin antagonist-1 (or the related analog AR-1) is administered intravenously at doses of 1-4 mg/kg, either before or after arrhythmia induction. Electrocardiogram (ECG) is monitored continuously. The primary endpoints are the time to onset of ventricular fibrillation, survival rate, and the reduction in the number of ventricular premature beats. A dose of 4 mg/kg given before ligation prevents ventricular fibrillation and increases survival to 100%.
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| ADME/Pharmacokinetics |
Detailed pharmacokinetic data for Calmodulin antagonist-1 is not available. As a small molecule calmodulin antagonist, it is expected to have moderate oral bioavailability and is often administered intraperitoneally or intravenously for in vivo studies. The compound is lipophilic and is likely to cross cell membranes readily. It is metabolized by hepatic cytochrome P450 enzymes. The terminal half-life in rodents is likely short (1-3 hours) due to extensive metabolism. Plasma protein binding is expected to be high due to its hydrophobic naphthalene sulfonamide structure.
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| Toxicity/Toxicokinetics |
Specific toxicology data for Calmodulin antagonist-1 is limited. The compound is known to be an antagonist of calmodulin, which is involved in numerous physiological processes. Potential toxicities at high doses may include disruption of cardiac function (as calmodulin is involved in excitation-contraction coupling), interference with cell cycle progression, and neuronal toxicity. The compound is classified as an inhibitor and should be handled with appropriate safety precautions. Standard safety assessment would include cytotoxicity assays on primary cell lines and a 14-day repeat-dose toxicity study in rodents.
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| References | |
| Additional Infomation |
Calmodulin antagonist-1 (W-7 hydrochloride) is a research-grade chemical and is not approved for clinical use. Its molecular formula is C14H18Cl2N2O2S with a molecular weight of 349.28 and a purity of ≥95%. The compound is a calmodulin (CaM) antagonist that inhibits calmodulin-activated Ca2+-phosphodiesterase (PDE) with an IC50 of 28-66 uM. It is a valuable research tool for studying the role of calmodulin in Ca2+ signaling, smooth muscle contraction, cell proliferation, and cardiac arrhythmias. The compound is stored at -20degC and is soluble in DMSO and slightly soluble in water upon heating.
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| Molecular Formula |
C14H18CL2N2O2S
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|---|---|
| Molecular Weight |
349.28
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| Exact Mass |
348.046
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| CAS # |
78957-84-3
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| PubChem CID |
9884715
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| Appearance |
Typically exists as Off-white to light yellow solids at room temperature
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| Boiling Point |
501.5ºC at 760 mmHg
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| Melting Point |
243-246ºC
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| Flash Point |
257.1ºC
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| LogP |
5.484
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| Hydrogen Bond Donor Count |
3
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| Hydrogen Bond Acceptor Count |
4
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| Rotatable Bond Count |
6
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| Heavy Atom Count |
21
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| Complexity |
397
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| Defined Atom Stereocenter Count |
0
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| SMILES |
C1=CC2=C(C=CC=C2Cl)C(=C1)S(=O)(=O)NCCCCN.Cl
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| InChi Key |
IKMXJMNRHREPOD-UHFFFAOYSA-N
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| InChi Code |
InChI=1S/C14H17ClN2O2S.ClH/c15-13-7-3-6-12-11(13)5-4-8-14(12)20(18,19)17-10-2-1-9-16;/h3-8,17H,1-2,9-10,16H2;1H
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| Chemical Name |
N-(4-aminobutyl)-5-chloronaphthalene-1-sulfonamide;hydrochloride
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| Synonyms |
78957-84-3; N-(4-aminobutyl)-5-chloro-1-naphthalenesulfonamide hydrochloride; Calmodulin antagonist-1; N-(4-Aminobutyl)-5-chloro-1-naphthalenesulfonamide HCl; N-(4-aminobutyl)-5-chloronaphthalene-1-sulfonamide hydrochloride; N-(4-Aminobutyl)-5-chloro-1-naphthalenesulphonamide hydrochloride; N-(4-aminobutyl)-5-chloronaphthalene-1-sulfonamide;hydrochloride; W-13 Isomer hydrochloride;
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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, 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: ~100 mg/mL (~286.3 mM; with ultrasonication)
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| Solubility (In Vivo) |
Solubility in Formulation 1: ≥ 2.5 mg/mL (7.16 mM) (saturation unknown) in 10% DMSO + 40% PEG300 + 5% Tween-80 + 45% Saline (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 DMSO stock solution (25.0 mg/mL) to 400 μL of PEG300 and mix well; then add 50 μL of Tween-80 and mix well; finally add 450 μL of physiological saline and 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. Solubility in Formulation 2: ≥ 2.5 mg/mL (7.16 mM) (saturation unknown) in 10% DMSO + 90% (20% SBE-β-CD in Saline) (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 DMSO stock solution (25.0 mg/mL) to 900 μL of 20% SBE-β-CD saline and mix well. Preparation of 20% SBE-β-CD in Saline (4°C，1 week): Dissolve 2 g SBE-β-CD in 10 mL saline to obtain a clear solution. Solubility in Formulation 3: ≥ 2.5 mg/mL (7.16 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 DMSO stock solution (25.0 mg/mL) to 900 μL of corn oil and mix well. (Please use freshly prepared in vivo formulations for optimal results.) |
| Preparing Stock Solutions | 1 mg | 5 mg | 10 mg | |
| 1 mM | 2.8630 mL | 14.3152 mL | 28.6303 mL | |
| 5 mM | 0.5726 mL | 2.8630 mL | 5.7261 mL | |
| 10 mM | 0.2863 mL | 1.4315 mL | 2.8630 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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