LL-37 5mg

LL-37 is the only human cathelicidin -- a class of host defense peptides that bridge innate immunity and antimicrobial defense. It is derived from the C-terminus of the hCAP-18 protein (human cathelicidin antimicrobial protein 18), processed by serine proteases into the active 37-amino acid LL-37 form. The name reflects its structure: it begins with two leucine residues (LL) and is 37 amino acids long. Despite being the sole human cathelicidin, it is expressed in neutrophils, epithelial cells of the skin, gut, lung, and urogenital tract -- providing frontline defense at multiple barrier sites.

LL-37's antimicrobial mechanism involves disruption of bacterial membranes. Its amphipathic alpha-helical structure allows it to insert into and permeabilize bacterial lipid bilayers, killing a broad spectrum of gram-positive and gram-negative bacteria, fungi, and enveloped viruses. It also binds and neutralizes bacterial LPS (endotoxin), a mechanism studied in models of endotoxin signalling. Beyond direct killing, LL-37 has extensive immunomodulatory functions -- it activates epithelial cells, macrophages, and dendritic cells, modulates TLR signaling, and is studied for fibroblast and angiogenesis responses in tissue-repair model systems.

Research interest spans antimicrobial-peptide biology, tissue-repair model systems, skin-barrier-model and lung host-defense research, anti-biofilm strategies, and oncology research (LL-37 has context-dependent pro- and anti-tumor effects in different cancer models).

Specifications

Storage

Store at -20°C. LL-37 can aggregate in high ionic strength solutions -- reconstitute in low-salt buffer or sterile water and then add buffer. Refrigerate at 2-8°C after reconstitution and use within 14 days. Avoid repeated freeze-thaw.

LL-37 is supplied for laboratory research use only. Not for human use. Handle in compliance with institutional biosafety guidelines.