| Size | Price | |
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| 500mg | ||
| 1g | ||
| Other Sizes |
| Targets |
Calpain-1 is a calcium-dependent cysteine protease (EC 3.4.22.52) that cleaves substrates at specific peptide bonds. It requires micromolar Ca²⁺ concentrations for activation. [1][2]
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| ln Vitro |
- Calpain-1 cleaves >200 cellular substrates (e.g., cytoskeletal proteins, kinases, phosphatases), with cleavage efficiency quantified by catalytic efficiency (\(k_{\text{cat}}/K_{\text{m}}\)) values derived from oligopeptide arrays. For example:
- Preferred cleavage site: P5-P4-P3-P2-↓-P1' (↓ = cleavage point), with Leu/Val at P2 and Tyr/Arg at P1' enhancing efficiency. [1]
- In neurons, Calpain-1 activation truncates glutamate receptors (e.g., GluA1 AMPAR subunit), altering synaptic plasticity. [2] - Enzymatic activity and substrate specificity: Using quantitative structure-activity relationship (QSAR) analysis, Calpain-1's cleavage sites and catalytic efficiencies (kcat/km) on 84 20-mer oligopeptides were determined. Calpain-1 exhibited preference for hydrophobic amino acids at the P2 site (e.g., Leu/Ile) and higher cleavage efficiency on substrates with longer N-terminal sequences. The kcat/km values for 360 newly identified sites ranged from 12.5–1,710 M⁻¹s⁻¹. [1] - Synaptic plasticity regulation: Calpain-1 activation is essential for long-term potentiation (LTP) induction in hippocampal neurons. It modulates glutamate receptor trafficking and cytoskeletal remodeling through local protein synthesis, enhancing synaptic transmission. [2] |
| ln Vivo |
- Calpain-1 cleaves >200 cellular substrates (e.g., cytoskeletal proteins, kinases, phosphatases), with cleavage efficiency quantified by catalytic efficiency (\(k_{\text{cat}}/K_{\text{m}}\)) values derived from oligopeptide arrays. For example:
- Preferred cleavage site: P5-P4-P3-P2-↓-P1' (↓ = cleavage point), with Leu/Val at P2 and Tyr/Arg at P1' enhancing efficiency. [1]
- In neurons, Calpain-1 activation truncates glutamate receptors (e.g., GluA1 AMPAR subunit), altering synaptic plasticity. [2] - Neuroprotection: In focal cerebral ischemia models, Calpain-1 activation confers neuroprotection by inhibiting caspase-3-mediated apoptosis, reducing infarct volume, and improving neurological outcomes. [2] - Learning and memory: Calpain-1 knockout mice showed impaired spatial memory in the Morris water maze, characterized by prolonged escape latency and reduced target quadrant dwell time, indicating its critical role in hippocampus-dependent learning. [2] |
| Enzyme Assay |
- Oligopeptide array-based profiling:
1. Synthesize a library of tetradecapeptides with diverse sequences.
2. Incubate peptides with purified Calpain-1 in Ca²⁺-containing buffer (pH 7.5).
3. Quantify cleavage products via mass spectrometry and calculate catalytic efficiency (\(k_{\text{cat}}/K_{\text{m}}\)). [1]
- Substrate specificity assay: - Use fluorogenic substrates (e.g., Suc-Leu-Tyr-AMC) to measure hydrolysis kinetics. - Determine kinetic parameters (\(K_{\text{m}}\), \(V_{\text{max}}\)) under varying Ca²⁺ concentrations. [1] - Catalytic efficiency measurement: Recombinant Calpain-1 was incubated with fluorescently labeled substrates (e.g., Dabcyl-GPLGVRGQ-EDANS) in Ca²⁺-containing buffer. LC-MS analysis of cleavage products revealed that Calpain-1's kcat/km for 360 novel sites spanned 12.5–1,710 M⁻¹s⁻¹. [1] - Substrate specificity comparison: By comparing Calpain-1 and Calpain-2's cleavage patterns, Calpain-1 showed distinct preferences at P9-P7/P2/P5' sites, such as hydrophobic residues at P2, while Calpain-2 favored polar residues. [1] |
| Cell Assay |
- Neuronal culture analysis:
1. Treat primary cortical neurons with glutamate (100 µM) to induce Ca²⁺ influx. 2. Detect Calpain-1 activation via western blot (cleaved α-spectrin fragment at 145 kDa). 3. Assess synaptic protein degradation (e.g., PSD-95, GluA1) using immunocytochemistry. [2] - LTP induction in hippocampal neurons: High-frequency stimulation (HFS) induced LTP in primary hippocampal cultures. Addition of Calpain-1 inhibitor (e.g., Calpeptin) blocked LTP formation, whereas activator (A23187) enhanced LTP magnitude. [2] - Apoptosis detection: In oxygen-glucose deprivation (OGD) models, Calpain-1 activation promoted neuronal apoptosis via α-fodrin cleavage. Annexin V/PI staining showed inhibitors reduced early apoptotic cells by 40–60%. [2] |
| Animal Protocol |
- Calpain-1 knockout mice:
1. Generate Capn1⁻/⁻ mice on a C57BL/6 background. 2. Subject mice to Morris water maze for spatial memory testing. 3. Analyze hippocampal slices for LTP using electrophysiology. [2] - Neurodegeneration model: 1. Inject Aβ oligomers into mouse hippocampus. 2. Administer calpain inhibitor MDL-28170 (10 mg/kg, IP) daily. 3. Harvest brains for histology and western blot of tau cleavage. [2] - Cerebral ischemia model: Rats underwent 2-hour middle cerebral artery occlusion (MCAO) followed by 24-hour reperfusion. Calpain-1 inhibitor administration reduced infarct volume by 30–40% (TTC staining) and improved motor function (mNSS score). [2] - Behavioral testing in knockout mice: Calpain-1 knockout mice exhibited impaired spatial memory in the Morris water maze, with longer escape latencies and decreased target quadrant visits compared to wild-type controls. [2] |
| ADME/Pharmacokinetics |
Calpeptin has good blood-brain barrier penetration, a half-life of about 2.5 hours, and is mainly eliminated through renal excretion. [2]
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| Toxicity/Toxicokinetics |
Acute toxicity: A single intraperitoneal injection of a calpain-1 inhibitor (dosage not specified) did not cause toxicity or weight loss in mice. [2] Subchronic tolerance: Four weeks after administration, blood biochemical indicators (ALT, AST, BUN) and hematological parameters returned to normal, indicating good tolerance. [2]
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| References |
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| Additional Infomation |
- Calpain-1 knockout mice: 1. Capn1⁻/⁻ mice were constructed on a C57BL/6 background. 2. The mice were subjected to the Morris water maze spatial memory test. 3. Long-term duration enhancement (LTP) in hippocampal slices was analyzed using electrophysiological techniques. [2]
- Neurodegenerative disease model: 1. Aβ oligomers were injected into the hippocampus of mice. 2. The calpain inhibitor MDL-28170 (10 mg/kg) was administered intraperitoneally daily. 3. Brain tissue was removed for histological analysis and Western blot detection of tau protein cleavage. [2] |
| CAS # |
689772-75-6
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|---|---|
| Appearance |
Typically exists as solid at room temperature
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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 |
| 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) |
May dissolve in DMSO (in most cases), if not, try other solvents such as H2O, Ethanol, or DMF with a minute amount of products to avoid loss of samples
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| Solubility (In Vivo) |
Note: Listed below are some common formulations that may be used to formulate products with low water solubility (e.g. < 1 mg/mL), you may test these formulations using a minute amount of products to avoid loss of samples.
Injection Formulations
Injection Formulation 1: DMSO : Tween 80： Saline = 10 : 5 : 85 (i.e. 100 μL DMSO stock solution → 50 μL Tween 80 → 850 μL Saline)(e.g. IP/IV/IM/SC) *Preparation of saline: Dissolve 0.9 g of sodium chloride in 100 mL ddH ₂ O to obtain a clear solution. Injection Formulation 2: DMSO : PEG300 ：Tween 80 : Saline = 10 : 40 : 5 : 45 (i.e. 100 μL DMSO → 400 μLPEG300 → 50 μL Tween 80 → 450 μL Saline) Injection Formulation 3: DMSO : Corn oil = 10 : 90 (i.e. 100 μL DMSO → 900 μL Corn oil) Example: Take the Injection Formulation 3 (DMSO : Corn oil = 10 : 90) as an example, if 1 mL of 2.5 mg/mL working solution is to be prepared, you can take 100 μL 25 mg/mL DMSO stock solution and add to 900 μL corn oil, mix well to obtain a clear or suspension solution (2.5 mg/mL, ready for use in animals). View More
Injection Formulation 4: DMSO : 20% SBE-β-CD in saline = 10 : 90 [i.e. 100 μL DMSO → 900 μL (20% SBE-β-CD in saline)] Oral Formulations
Oral Formulation 1: Suspend in 0.5% CMC Na (carboxymethylcellulose sodium) Oral Formulation 2: Suspend in 0.5% Carboxymethyl cellulose Example: Take the Oral Formulation 1 (Suspend in 0.5% CMC Na) as an example, if 100 mL of 2.5 mg/mL working solution is to be prepared, you can first prepare 0.5% CMC Na solution by measuring 0.5 g CMC Na and dissolve it in 100 mL ddH2O to obtain a clear solution; then add 250 mg of the product to 100 mL 0.5% CMC Na solution, to make the suspension solution (2.5 mg/mL, ready for use in animals). View More
Oral Formulation 3: Dissolved in PEG400 (Please use freshly prepared in vivo formulations for optimal results.) |
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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