Protegrin

Protegrins were first discovered in porcine leukocytes and were found to have antimicrobial activity against bacteria, fungi, and some enveloped viruses.

[2] Their secondary structure is classified as cysteine-rich β-sheet antimicrobial peptides, AMPs, that display limited sequence similarity to certain defensins and tachyplesins.

[3] Recent studies suggest that protegrins can bind to lipopolysaccharide, a property that may help them to insert into the membranes of gram-negative bacteria and permeabilize them.

[13] The protegrins are highly microbicidal against Candida albicans,[14] Escherichia coli,[15] Listeria monocytogenes, Neisseria gonorrhoeae,[16] and the virions of the human immunodeficiency virus in vitro under conditions which mimic the tonicity of the extracellular milieu.

[1][5][17] The mechanism of this microbicidal activity is believed to involve membrane disruption, similar to many other antibiotic peptides [5][18] Protegrin-1 (PG-1) peptidomimetics developed by Polyphor AG and the University of Zurich are based on the use of the beta hairpin-stabilizing D-Pro-L-Pro template which promote a beta hairpin loop structure found in PG-I.