LL-37 (Cathelicidin)

Description

Cationic antimicrobial peptide for immune and wound healing research.

LL-37, also known as cathelicidin, is a 37-amino acid cationic antimicrobial peptide (AMP) derived from the C-terminal cleavage of human cathelicidin precursor protein hCAP18. It is the only cathelicidin-derived AMP found in humans and is expressed by neutrophils, epithelial cells, and macrophages. LL-37 kills pathogens through electrostatic interaction with negatively charged microbial membranes, forming toroidal pores that compromise membrane integrity. Beyond direct antimicrobial activity, it modulates innate immunity by acting as a chemoattractant, promoting angiogenesis, and neutralizing bacterial endotoxin (LPS). Research by Zanetti (2004) in Journal of Leukocyte Biology provided a comprehensive characterization of cathelicidin biology and LL-37's multifunctional role in innate defense. Studies in The Journal of Immunology demonstrated that LL-37 exhibited broad-spectrum activity against gram-positive bacteria, gram-negative bacteria, fungi, and enveloped viruses, with minimum inhibitory concentrations in the low micromolar range. Heilborn et al. published findings in Journal of Investigative Dermatology showing that LL-37 expression was significantly reduced in chronic wound beds, and exogenous application promoted re-epithelialization in wound models. Compared to other antimicrobial peptides like defensins (HBD-1, HBD-2), LL-37 has a broader spectrum of activity and more pronounced immunomodulatory effects. Unlike conventional antibiotics, LL-37's membrane-disrupting mechanism makes resistance development unlikely, an increasingly important consideration in antimicrobial research. Store lyophilized LL-37 at -20°C, protected from moisture. Reconstitute with sterile bacteriostatic water and keep at 2-8°C, using within 3 weeks due to potential aggregation. LL-37 is studied by infectious disease researchers, wound healing scientists, immunologists, and antimicrobial resistance specialists investigating peptide-based alternatives to conventional antibiotics.

This product is supplied as a lyophilized powder and is intended for laboratory and research use only. Not for human consumption. Each vial contains 5mg of research-grade material.

Research Applications

• Antimicrobial activity against bacteria, fungi, viruses
• Inflammatory response modulation
• Wound healing and tissue repair
• Cancer immunotherapy adjuvant research

Specifications

Size

5mg

Purity

≥98% (HPLC)

Form

Lyophilized Powder

Molecular Formula

C205H340N50O53

Molecular Weight

4493.34 g/mol

Storage & Handling

• Long-term storage: -20°C in a sealed, light-protected container
• Short-term storage: 2-8°C (refrigerated) for up to 30 days
• Reconstituted: Store at 2-8°C and use within 30 days
• Avoid: Repeated freeze-thaw cycles, direct sunlight, and moisture exposure
• Reconstitution: Use bacteriostatic water or sterile water for injection