LL37

LL37 is a synthetic research peptide, a 37-residue amphipathic cationic antimicrobial peptide belonging to the cathelicidin family.  It is the only cathelicidin-type peptide found in humans, corresponding to amino acids 134-170 of the human cationic antimicrobial protein 18 (hCAP18). LL-37 plays a key role in the first line of defense against local infection and systemic invasion of pathogens at sites of inflammation and wounds. The peptide exhibits a broad spectrum of antimicrobial activity against bacteria, fungi, and viruses, and is widely studied for its additional roles in immunomodulation, wound healing, and cancer research.

LL-37 exerts its effects through multiple interconnected mechanisms. The primary antimicrobial mechanism involves disruption of microbial cell membranes through electrostatic interactions and pore formation. The peptide's cationic and α-helical structure allows it to interact with negatively charged microbial membranes, leading to membrane permeabilization, cell wall destruction, oxidative stress, and biofilm suppression. Beyond its direct antimicrobial effects, LL-37 modulates innate immunity through binding and inactivation of bacterial endotoxins and promoting chemotaxis of immune cells. It also exerts anti-inflammatory effects, chemo-attraction, and promotes wound healing and closure at infected sites.

• Antimicrobial Research: Investigated for its broad-spectrum activity against over 38 bacteria, 16 fungi, and 16 viruses, including antibiotic-resistant strains.
• Immunomodulation: Employed to study innate immune responses, chemotaxis, LPS neutralization, and inflammatory response modulation.
• Wound Healing: Studied for promoting wound healing, protecting cornea from infection, and regulating tissue repair processes.
• Cancer Research: Investigated for its anticancer effects and role in cancer immunity.
• Biofilm Studies: Utilized as a validated positive control for biofilm prevention and inhibition studies.

CAS Number: 154947-66-7
PubChem CID: 137699680
Molecular Formula: C₂₀₅H₃₄₀N₆₀O₅₃
Molecular Weight: 4,493.26 g/mol
Sequence: Leu-Leu-Gly-Asp-Phe-Phe-Arg-Lys-Ser-Lys-Glu-Lys-Ile-Gly-Lys-Glu-Phe-Lys-Arg-Ile-Val-Gln-Arg-Ile-Lys-Asp-Phe-Leu-Arg-Asn-Leu-Val-Pro-Arg-Thr-Glu-Ser (LLGDFFRKSKEKIGKEFKRIVQRIKDFLRNLVPRTES)
Purity: ≥ 99%
Form: Lyophilized powder
Storage: Store at ≤ -20°C in a cool, dry place, protected from light and moisture
Solubility: Soluble in sterile water; prepare working solutions per laboratory protocol