| Size | Price | Stock | Qty |
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| 1mg |
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| 5mg |
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| 10mg |
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| Other Sizes |
| Targets |
LL-37 targets microbial membranes. It also interacts with various host receptors, including formyl peptide receptor-like 1 (FPRL1), P2X7, and the epidermal growth factor receptor (EGFR), thereby modulating immune cell chemotaxis and cytokine release.
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| ln Vitro |
The migration of HCECs is impacted by LL-37, human TFA (1–20 μg/mL; 24 h) [2]. HCECs' production of cytokines is influenced by LL-37, human TFA (0.0001–5 μg/mL; 6–24 h) [2]. When applied to HCECs at concentrations more than 10 μg/mL, LL-37, human TFA (1-100 μg/mL; 24 h), demonstrates dose-dependent cytotoxicity[2].
LL-37, human TFA exhibits broad-spectrum antimicrobial activity against bacteria (Gram-positive and Gram-negative), viruses, and fungi. It also influences immune cell chemotaxis and cytokine release. LL-37 protects the cornea from infection and modulates wound healing. In HCECs (human corneal epithelial cells), LL-37 (1-20 ug/mL, 24h) affects cell migration and (0.0001-5 ug/mL, 6-24h) affects cytokine secretion. |
| ln Vivo |
Mice with pneumonia caused by MRSA are treated better with LL-37, human TFA (0.4-2.0 mg/kg; intratracheal injection once) [3].
LL-37, human TFA (0.4-2.0 mg/kg; intratracheal injection, once) improves MRSA-induced pneumonia in mice. It decreases IL-6 and TNF-alpha release, thereby attenuating MRSA-induced pneumonia. The amount of LL-37 produced by neutrophils is also shown to be upregulated in severe congenital neutropenia. |
| Enzyme Assay |
For non-cell binding assays, the antimicrobial activity of LL-37 can be tested against a panel of bacteria and fungi. Standard minimum inhibitory concentration (MIC) assays are performed in 96-well plates. Serial dilutions of LL-37 (0.5-128 ug/mL) are prepared in broth (e.g., Mueller-Hinton broth). Bacterial suspensions are added (5×10⁵ CFU/mL), and the plates are incubated at 37degC for 16-24 hours. The MIC is the lowest concentration that prevents visible growth. For receptor binding, LL-37 can be labeled with a fluorophore (e.g., FITC) and used in flow cytometry or confocal microscopy to study binding to cells expressing receptors like FPRL1.
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| Cell Assay |
Cell Migration Assay [2]
Cell Types: Human corneal epithelial cell(HCEC) Tested Concentrations: 1, 2.5, 5, 10 and 20 μg/mL Incubation Duration: 24 hrs (hours) Experimental Results: Dose-dependently stimulated HCECs migration but demonstrated no effect on cell proliferation. Cell Viability Assay[2] Cell Types: Human corneal epithelial cell(HCEC) Tested Concentrations: 0.0001, 0.001, 0.01, 0.1, 0.5, 1, and 5 μg/mL Incubation Duration: 6 and 24 hrs (hours) Experimental Results: Dose-dependently increased IL -8, IL-6, IL-1β and TNF-α secretion at 6 and 24 hrs (hours) in HCECs. For cellular assays, HCEC (human corneal epithelial cell) migration assays are performed using a scratch wound-healing assay: cells are grown to confluence, a scratch is made with a pipette tip, and the cells are treated with LL-37 (1-20 ug/mL) for 24 hours. The migration distance is measured. Cytokine secretion (IL-8, IL-6, IL-1beta, TNF-alpha) is measured by ELISA after treating HCECs with LL-37 (0.0001-5 ug/mL, 6-24h). Cytotoxicity is measured by treating cells with LL-37 (1-100 ug/mL, 24h) and using an LDH release assay or MTT assay (dose-dependent cytotoxicity observed above 10 ug/mL). For macrophage assays, THP-1 cells differentiated into macrophages are treated with LL-37, and the expression of surface markers (CD86, CD206) is analyzed by flow cytometry. |
| Animal Protocol |
Animal/Disease Models: 6-8 week-old C57BL/6 mice with MRSA-induced pneumonia[3]
Doses: 0.4, 0.8, 1.2, 1.6 and 2.0 mg/kg Route of Administration: Intracheal injection; 0.4-2.0 mg/kg once Experimental Results: diminished IL-6 and TNF-α release to attenuated MRSA-induced pneumonia of testing mice. For in vivo animal studies, 6-8 week-old C57BL/6 mice are used in a MRSA-induced pneumonia model. Mice are infected intratracheally with MRSA (5×10⁷ CFU). LL-37, human TFA (0.4, 0.8, 1.2, 1.6, and 2.0 mg/kg) is administered intratracheally immediately after infection (once). At 24 hours post-infection, mice are euthanized. Bronchoalveolar lavage (BAL) fluid is collected for bacterial count and cytokine (IL-6, TNF-alpha) analysis. Lung tissue is collected for histopathology. LL-37 improves MRSA-induced pneumonia in mice. |
| ADME/Pharmacokinetics |
LL-37 is a 37-residue peptide (MW ~4607 Da). As a peptide, it has a short plasma half-life (minutes) due to proteolytic degradation and rapid renal clearance. The TFA salt form improves solubility and handling. It is typically administered locally (topically, intratracheally) to achieve high local concentrations. Detailed ADME data is not available.
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| Toxicity/Toxicokinetics |
LL-37 shows dose-dependent cytotoxicity in HCECs at concentrations over 10 ug/mL. In animal studies, intratracheal administration of 2.0 mg/kg is well-tolerated. Local administration may cause mild inflammation. The TFA counterion may be irritating.
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| References |
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| Additional Infomation |
LL-37 is the only human cathelicidin antimicrobial peptide. Its multiple functions include direct antimicrobial activity and immunomodulation. It is being studied for its potential in treating infections and promoting wound healing. The TFA salt is a common form for research. The product is for research use only; not for human use.
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| Molecular Formula |
C205H340N60O53.XC2HF3O2
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| Molecular Weight |
4493.26 (free base)
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| Related CAS # |
LL-37, human;154947-66-7;LL-37, human acetate
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| Appearance |
White to off-white solid powder
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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) |
H2O :~100 mg/mL
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| Solubility (In Vivo) |
Solubility in Formulation 1: 16.67 mg/mL (Infinity mM) in PBS (add these co-solvents sequentially from left to right, and one by one), clear solution; with sonication.
(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.
Products are for research use only; We do not sell to patients
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