LL-37

LL-37, also known as Cathelicidin, is a cationic peptide composed of 37 amino acids and is primarily found in neutrophils.(1) The peptide appears to be produced by the extracellular breakdown of the hCAP18 proteins caused by protease enzymes. Researched for its potential antimicrobial characteristics, the peptide appears to form agglomerates and lipid bilayers, which may prevent it from easily degrading and protect it from enzymatic action.(1)

Overview Antimicrobial peptides are structured with the potential to fight against bacteria, fungi, and some virus strains. These peptides may interact with targets in a non-specific fashion, which supports researchers’ belief that once the peptide is introduced, pathogens are unable to develop resistance against these peptides.(2)

LL-37 is a α-helical peptide that scientists believe is required to maintain immunity against all microbes.(3) To understand the functioning of the peptide, a peptide model was created as part of a study(4) based on the assumption that the peptide might interact directly with the bacterial membrane. This study suggested that the peptide first interacts with the lipids on the bacterial membrane via electrostatic characteristics, followed by lateral diffusion and consequent assembly of the peptide on the membrane. This potential interaction may lead to membrane interference and degradation of the bacterial cell.

Several other studies hypothesize how the peptide interacts with microbial membranes, including pore formation on the membrane(3)(5) and extreme membrane disruption caused by the peptide and lipid complexes.(6) These studies universally suggest that peptides have the potential to interact with the microbial membrane, leading to membrane breakdown.

Chemical Makeup Molecular Formula: C205H340N50O53 Molecular Weight: 4493.34 g/mol Other Known Titles: CAP-18