LL-37

LL-37 Research Peptide (Cathelicidin)
Lyophilized Format • ≥99% HPLC Purity • Ships in 1–2 Business Days • U.S. Warehouses

LL-37 (CAP-18, hCAP18, CAS 154947-66-7) is a 37 amino acid human cathelicidin-derived antimicrobial peptide corresponding to the 134–170 segment of human cationic antimicrobial protein 18 (hCAP18), supplied by Nextday Peptides for laboratory and analytical research applications. The only known human member of the cathelicidin family of antimicrobial peptides, LL-37 is distinguished by its amphipathic alpha-helical structure and broad-spectrum activity in experimental models. Each vial is independently verified to ≥99% HPLC purity with a Certificate of Analysis available on request. For scientific research use only.

Compound Specifications

Why Research Laboratories Select LL-37

LL-37 is the only known human member of the cathelicidin family of antimicrobial peptides, making it one of the most unique and widely studied peptides in innate immunity and antimicrobial research. Its amphipathic alpha-helical structure — which allows interaction with anionic lipid surfaces and microbial envelope components — makes it a valuable tool for laboratories investigating antimicrobial membrane disruption mechanisms, immunomodulatory signaling, and epithelial biology in preclinical settings.

• Only known human cathelicidin — the sole human member of the cathelicidin antimicrobial peptide family
• 37 amino acid amphipathic alpha-helical structure — studied for membrane interaction and LPS binding in research models
• Studied in preclinical models examining antimicrobial membrane disruption, chemotactic signaling, and cytokine network modulation
• Cell permeable — referenced in intracellular signaling and endothelial biology research models
• Significantly resistant to proteolytic degradation in solution — useful for diverse experimental protocols
• Referenced in peer-reviewed literature including Biochimica et Biophysica Acta, Nature Medicine, and ACS Infectious Diseases
• Lyophilized format ensures stability and reproducibility across experimental runs
• Batch and lot identifiers on all labeling for full laboratory documentation compliance

Research Background

LL-37 was first described as a cathelicidin-derived antimicrobial peptide in the 1990s. Dürr et al. (2006) published a comprehensive review of LL-37 biology in Biochimica et Biophysica Acta, establishing its role as the only human cathelicidin. Preclinical studies have examined its antimicrobial activity against gram-positive and gram-negative bacteria, LPS neutralization mechanisms, FPRL1-mediated chemotaxis of immune cells, and angiogenic signaling via endothelial PGE2 pathways. Wang et al. (2021) examined LL-37’s interaction with SARS-CoV-2 receptor binding domain in ACS Infectious Diseases. All information provided here is for educational and reference purposes only and does not constitute medical or clinical guidance.

Reference sources: PubChem — LL-37 (CID 16198951) | NIH PMC — LL-37 Antimicrobial and Anti-Biofilm Review

Shipping & Fulfillment

• Ships from U.S. warehouses — Florida, North Carolina, and California
• Overnight and 2-day shipping available at checkout
• Same-day processing on orders placed before 3:30 PM ET
• Discreet packaging with full tracking provided
• Bulk research orders welcome — contact us for volume pricing

Storage & Handling

• Store lyophilized peptide at -20°C away from light and moisture
• After reconstitution store at -20°C and use within 1 month — aliquot to avoid repeated freeze-thaw cycles
• Minimize time at ambient temperature during handling to preserve compound integrity
• Handle using appropriate laboratory safety protocols
• Keep containers sealed when not in use

Frequently Asked Questions

For Research Use Only — Not for human or veterinary consumption • Not evaluated by the FDA • Supplied by Nextday Peptides for laboratory research applications only