LL-37

LL-37

Primary Function: Antimicrobial defense, immune modulation, and tissue repair
Research Use: Infection models, wound healing, autoimmune modulation, respiratory health
Molecular Formula: C219H377N65O46
CAS Number: 219685-51-7
Synonyms: CAP-18 (37–68), Cathelicidin antimicrobial peptide, hCAP-18 fragment

Description:
LL-37 is a cationic antimicrobial peptide (AMP) derived from the human cathelicidin protein hCAP-18. It plays a critical role in the innate immune system, offering broad-spectrum antimicrobial, antiviral, and antifungal activity. In addition to its role in host defense, LL-37 also promotes wound healing, angiogenesis, and immune regulation, making it a focus in research areas ranging from infectious disease to skin regeneration and chronic inflammation.

Mechanism of Action:

• Disrupts microbial membranes via amphipathic structure
• Neutralizes bacterial endotoxins (e.g., LPS)
• Stimulates cytokine modulation and tissue remodeling
• Enhances epithelial barrier integrity and promotes keratinocyte migration

Key Research Areas:

• Skin infections and chronic wound healing
• Respiratory infections (e.g., influenza, SARS-CoV-2 models)
• Immune tolerance and autoimmune modulation
• Inflammatory skin conditions such as rosacea and psoriasis

History of Discovery:
LL-37 was first isolated in the 1990s as the only human cathelicidin peptide. Discovered by researchers studying leukocyte responses to pathogens, LL-37 emerged as a central molecule in epithelial immunity. It is now studied in fields ranging from dermatology to immunology due to its ability to fight infection while modulating immune response and promoting tissue healing.

Case Studies:

1. Enhanced Wound Closure (2007, J Invest Dermatol): LL-37 accelerated re-epithelialization and neovascularization in skin injury models. [J Invest Dermatol. 2007;127(10):2425–2431.]
2. Antiviral Activity Against Influenza (2012, PLoS One): LL-37 inhibited influenza A viral replication and reduced lung inflammation in murine models. [PLoS One. 2012;7(10):e47252.]
3. Psoriasis Immunomodulation (2015, J Immunol): LL-37 altered T-cell activation and cytokine profiles in psoriatic lesions. [J Immunol. 2015;194(11):5444–5453.]

Packaging Information:

• Form: Lyophilized powder
• Purity: ≥ 99%
• Storage: Store at -20°C in a dry, dark environment
• For research use only. Not for human or veterinary use.