LL-37 Complex (5mg)

What is LL‑37 Complex?

LL‑37 Complex contains the human cathelicidin antimicrobial peptide LL‑37—a 37–amino-acid, cationic, amphipathic sequence derived from the C-terminus of the precursor protein hCAP18. Naturally produced by epithelial cells, neutrophils, and macrophages, LL‑37 is extensively used in preclinical research for its antimicrobial, immunomodulatory, and regenerative properties.

Chemical Structure of LL‑37 Complex

LL‑37 consists of 37 amino acids (LLGDFFRKSKEKIGKEFKRIVQRIKDFLRNLVPRTES) and adopts an α-helical structure (residues 2–31) upon interaction with lipid membranes. The amphipathic helix aligns hydrophobic and positively charged residues on opposing faces, enabling membrane insertion—a process visualized by NMR (PDB ID 2K6O) in anionic lipid micelles.

What Are the Effects of LL‑37 Complex?

• Broad-Spectrum Antimicrobial Action: LL‑37 disrupts microbial membranes and exhibits potent activity against bacteria, fungi, and viruses in vitro.
• Immunomodulatory Regulation: LL‑37 interacts with immune receptors like FPRL‑1 and P2X7, influencing chemotaxis, cytokine production, innate immunity, and interferon responses.
• Biofilm Disruption & Resistance Potential: It prevents biofilm formation and disassembles existing biofilms, making it a promising molecule in antimicrobial research targeting resistant organisms.
• Peptide Self‑Assembly: A core segment (residues 17–29) self‑assembles into helical peptide fibrils, retaining antibacterial activity and suggesting functional structural organization in bioactive states.

Citations

1. RCSB Protein Data Bank – “Structure of LL‑37 in lipid micelles (NMR, PDB ID 2K6O); demonstrates amphipathic α-helix in membrane context.” LL‑37 Complex Overview
2. MDPI Biomolecules (2024); 14(3):320 – “LL‑37: antimicrobial activity, immune modulation, biofilm inhibition.” LL‑37 Complex Overview
3. Springer – “Immunomodulatory Antimicrobial Peptide LL‑37.” In: Peptides as Immune Modulators (2020) LL‑37 Complex Overview
4. Biochemistry (2006); 45(10):3385–3392 – “Structure of LL‑37 and its interaction with membranes via NMR.” LL‑37 Complex Overview
5. Nature Communications (2020); 11:3894 – “LL‑37(17–29) forms antimicrobial helical fibrils.” LL‑37 Complex Overview
6. Antibiotics (2021); 10(6):650 – “LL‑37: antimicrobial and anti-biofilm agent with resistance-combat potential.” LL‑37 Complex Overview
7. FASEB Journal (2006); 20(14):2068–2080 – “LL‑37 activates FPRL‑1 and P2X7 receptors—modulates chemotaxis and cytokine responses.” LL‑37 Complex Overview