LL-37
Product Name: LL-37
CAS No.: 597562-32-8
Synonym: Human LL-37, Antibacterial Protein LL-37 Amide, Cathelicidin LL-37
Document Version: V1.0
Application Scope: For Laboratory Research Only
Release Date: 2026
1. Basic Chemical Information
Test Item | Specification |
|---|
Full Name | LL-37 (Human Cathelicidin Antimicrobial Peptide) |
Chemical Name | Antibacterial protein LL-37 amide (human) |
Molecular Formula | C₂₀₅H₃₄₁N₆₁O₅₂ |
Molecular Weight | 4492.28 Da (free base) |
Full Amino Acid Sequence | H-Leu-Leu-Gly-Asp-Phe-Phe-Arg-Lys-Ser-Lys-Glu-Lys-Ile-Gly-Lys-Glu-Phe-Lys-Arg-Ile-Val-Gln-Arg-Ile-Lys-Asp-Phe-Leu-Arg-Asn-Leu-Val-Pro-Arg-Thr-Glu-Ser-OH |
Peptide Structure | Linear 37-amino-acid endogenous cationic antimicrobial peptide, human cathelicidin-derived peptide |
Biological Function | Multifunctional host defense peptide with broad-spectrum antibacterial, antiviral and anti-inflammatory activities. Regulates immune response, promotes epithelial wound healing, inhibits biofilm formation, widely used in antimicrobial mechanism, immunology, dermatology and inflammatory disease research |
2. Physical Characteristics
Appearance: White to off-white lyophilized crystalline powder
Odor: Odorless
Solubility: Freely soluble in sterile purified water and neutral PBS buffer (pH 6.5–8.0); soluble in ethanol; partially soluble in DMSO; insoluble in non-polar organic solvents
Aqueous Solution pH (1 mg/mL): 6.0 – 8.0
Hygroscopicity: Highly hygroscopic. Keep tightly sealed, dry and dark environment, avoid moisture absorption and repeated air exposure
3. Quality Specifications
Test Item | Test Method | Standard Specification |
|---|
Identity | RP-HPLC, ESI-MS | Match with standard reference; MW tolerance ±2 Da |
Purity (HPLC Area) | RP-HPLC | ≥99.0% |
Maximum Single Impurity | RP-HPLC | ≤0.50% |
Total Impurities | RP-HPLC | ≤2.0% |
Peptide Assay Content | HPLC / Titration | 98.0% – 102.0% |
Water Content | Karl Fischer | ≤1.0% |
Residual TFA/Acetate | Ion Chromatography | ≤0.5% |
Endotoxin | LAL Test (USP <85>) | ≤10 EU/mg |
Heavy Metals | ICP-MS | Pb,As,Cd,Hg ≤10 ppm each |
Residual Organic Solvents | GC | Compliant with ICH Q3C standard |
Amino Acid Composition | Amino Acid Analyzer | Within ±10% theoretical value |
4. Storage & Stability Conditions
4.1 Lyophilized Powder (Original Package)
Long-term Storage: ≤ -80℃, sealed, dry and dark environment, shelf life: 24 months
Medium-term Storage: -20℃, sealed and desiccated, shelf life: 12 months
Note: Avoid repeated freezing and thawing cycles, strictly prevent moisture absorption
4.2 Reconstituted Aqueous Solution
5. Stock Solution Preparation
Molecular Weight: 4492.28 Da
1 mM Standard Solution: Weigh 4.492 mg LL-37 powder, dissolve in 1 mL sterile purified water or PBS buffer
Recommended Solvent: Sterile purified water / pH 7.0-7.4 PBS buffer
Operation Tip: Gentle shaking and fresh preparation are recommended to ensure complete dissolution and biological activity for antimicrobial and immunological experiments.
6. Safety Handling & Disclaimer
This synthetic antimicrobial peptide is slightly irritant to eyes, skin and respiratory mucosa.
Wear standard PPE: lab coat, nitrile gloves, safety goggles during operation.
Avoid inhalation of powder dust and direct skin contact.
Waste materials shall be disposed in accordance with local chemical waste management regulations.
Strict Disclaimer: This product is only for scientific laboratory research. Not for human clinical use, medication or veterinary application.
7. HPLC Analytical Test Conditions
Column: C18 Analytical Column (250×4.6mm, 5μm)
Mobile Phase A: 0.1% TFA in Water
Mobile Phase B: 0.1% TFA in Acetonitrile
Detection Wavelength: 220 nm / 280 nm
Flow Rate: 1.0 mL/min
Column Temperature: 30℃
8. Analytical Spectrum Characterization
8.1 RP-HPLC Chromatogram
Sharp and symmetric main peak with qualified impurity distribution. No obvious miscellaneous peaks, fully meets research-grade purity standards. Batch-specific HPLC chromatogram is available upon customer request.
8.2 NMR Spectroscopy (¹H-NMR / ¹³C-NMR)
Test solvent: D₂O / DMSO-d₆, 400–500 MHz. Characteristic chemical shifts of all amino acid residues in LL-37 sequence are consistent with target molecular structure, confirming structural integrity.
8.3 ESI-MS Identity Confirmation
Theoretical molecular weight: 4492.28 Da; Measured molecular weight tolerance ±2 Da, fully matches LL-37 peptide structural identity.
End of Document
