Cathelicidins are a family of antimicrobial proteins predominantly found in the peroxidasenegative granules of neutrophils. The cathelicidins are synthesized as preproproteins. Within
the neutrophils, they are stored in granules as inactive proforms after removal of the signal
peptide. The active biologic domains of the cathelicidins generally reside in the C-terminus.
The C-terminal antimicrobial peptides are activated when cleaved from the proforms of the
cathelicidins by serine proteases from azurophil granules. Human cationic antimicrobial
protein (hCAP)18 is the only human cathelicidin identified to date. The antibacterial Cterminus of hCAP-18, LL-37 (37 amino acids), has been shown to exert broad antimicrobial
activity towards gram-negative as well as gram-positive bacteria and to have synergistic
antibacterial effects with the defensins. For instance, deficiency in saliva LL-37 accords with
occurrence of periodontal disease in patients with morbus Kostmann. Moreover, it functions
as a chemotactic agent for neutrophils, monocytes and T cells. LL-37 is markedly resistant to
proteolytic degradation and to a limited extent also cytotoxic towards mammalian cells.
LL-37 was demonstrated to be present in plasma in levels from 25 – 250 ng/ml and to be
enhanced in infectious diseases.
This product is manufactured in Netherlands by Hycult Biotech.