Research Compound LL-37

Research Compound LL-37 is a laboratory material for analytical and in vitro work.

What is LL-37?

LL-37 is a 37-amino-acid peptide beginning with two leucines (hence the name), with a molecular weight of approximately 4.5 kDa. It is the only human cathelicidin, produced by cleavage of the C-terminal part of the precursor protein hCAP18, primarily by proteinase 3.

Research background

Human cathelicidin was described in the mid-1990s, a period when antimicrobial peptides were recognised as an important part of mammalian innate immunity. LL-37 has since become one of the most studied human antimicrobial peptides.

Mechanism and scientific context

In solution LL-37 forms a positively charged amphipathic alpha-helix, allowing it to interact with and disrupt negatively charged bacterial membranes. Beyond direct antimicrobial activity in vitro, it is studied as an immunomodulator: it binds lipopolysaccharide, influences chemotaxis and activates receptors such as FPR2.

Main research areas

• antimicrobial peptides and membrane interactions
• innate immunity
• immunomodulation and chemotaxis
• bacterial antibiotic resistance

Level of evidence

Strong mechanistic and preclinical literature. There is no basis for independent therapeutic use of the research material.

Research use only: for laboratory, analytical and in vitro research only; not for use in humans or animals. Guidance on batch documentation is available in our COA guide.