LL-37 is the sole endogenous cathelicidin-derived host defense peptide produced in the human body, cleaved from the C-terminal domain of human CAP18 precursor protein. As a core component of innate immunity, LL-37 possesses extremely broad biological activity far beyond ordinary antimicrobial peptides, making it one of the most widely studied immunomodulatory peptides in modern biochemistry, microbiology and tissue regeneration research.

Mechanistically, LL-37 is a cationic amphipathic peptide that selectively targets negatively charged microbial outer membranes. It disrupts lipid bilayer integrity, causes intracellular substance leakage, and exerts powerful bactericidal, fungicidal and antiviral effects against Gram-positive bacteria, Gram-negative bacteria, drug-resistant strains, biofilm-forming bacteria and enveloped viruses. Unlike traditional antibiotics that easily induce drug resistance, LL-37 acts through physical membrane destruction rather than single enzyme inhibition, providing a unique research model for exploring novel antibiotic alternative mechanisms.

In addition to antimicrobial activity, LL-37 is a critical immune regulatory factor. It mediates chemotaxis of neutrophils, macrophages and dendritic cells, modulates pro-inflammatory and anti-inflammatory cytokine balance, and regulates epithelial cell proliferation, migration and angiogenesis. It is widely used in laboratory studies involving skin barrier repair, mucosal inflammation, chronic wound healing, inflammatory disease mechanisms and immune homeostasis regulation. Its dual functions of sterilization and anti-inflammation make it irreplaceable in inflammation and tissue repair model research.

Our synthetic LL-37 is produced through high-precision solid-phase peptide synthesis, followed by multi-step reversed-phase HPLC purification and lyophilization process. As a long-chain high-charge peptide, LL-37 is prone to incomplete coupling, truncation and residual salt impurities during synthesis. We strictly control peptide folding integrity, remove residual TFA and synthesis by-products, and verify each batch via MS molecular weight matching and HPLC purity fingerprinting to ensure high consistency and repeatability for cell and animal experiments.

Lyophilized LL-37 exhibits excellent long-term structural stability under low-temperature dry conditions. However, after reconstitution, the peptide is highly sensitive to protease degradation, high temperature and repeated temperature changes. Aqueous solutions will gradually lose bioactivity if stored for extended periods. It is strongly recommended to prepare single-use aliquots immediately after dissolution, avoid freeze-thaw cycles, and operate under low-humidity conditions to prevent moisture-induced peptide denaturation.