LL-37: Research Overview and Mechanism
LL-37 is the human cathelicidin antimicrobial peptide, a 37-residue amphipathic helix studied in laboratory and preclinical research within innate immunity, host defense, membrane biophysics, and receptor-mediated immunomodulation. It is supplied as a lyophilized powder for research use only and is not approved for human use.
What LL-37 is
LL-37 is a 37-residue amphipathic, alpha-helical peptide (sequence LLGDFFRKSKEKIGKEFKRIVQRIKDFLRNLVPRTES), the mature antimicrobial fragment released by proteolytic cleavage from the human cathelicidin precursor hCAP18, the only cathelicidin found in humans. Its well-characterized structure makes it a reference host-defense peptide in innate-immunity research. Two CAS numbers circulate commercially for the same peptide, so the exact identifier should be confirmed against the Certificate of Analysis.
Pathways it is studied within
In research, LL-37 is studied along two complementary mechanistic lines. As a cationic amphipathic helix it partitions into and permeabilizes anionic microbial membranes, a direct antimicrobial behavior examined in membrane-biophysics models through carpet- and toroidal-pore descriptions of peptide-lipid interaction. Separately it is studied as an immunomodulator: it is chemotactic for immune cells through the formyl peptide receptor 2 (FPR2, also called FPRL1), it can neutralize bacterial lipopolysaccharide, and it is referenced in wound-healing, angiogenesis, and inflammatory-skin research literature.
These descriptions refer to antimicrobial-peptide and innate-immunity research applications, not to human effects, and the material here is for laboratory research only.
Handling and documentation
Pinnacle LL-37 ships as a 5mg lyophilized powder of the 37-residue cathelicidin (molecular formula C205H340N60O53, near 4493 g/mol). Its high content of lysine and arginine makes it strongly cationic, so it dissolves in water but can adsorb to glass and plastic and is best handled in low-binding vessels to keep working concentrations accurate. Because two CAS numbers circulate for the same peptide, reconcile the exact identifier and salt form against the lot-matched Certificate of Analysis. Store the sealed vial at -20°C protected from light and refrigerate the reconstituted solution.
All products are intended strictly for in-vitro laboratory research and development use only. Not for human or veterinary use, not a drug, food, or cosmetic, and not intended to diagnose, treat, cure, or prevent any disease.