Long before penicillin, animals, plants, and fungi were making their own antibiotics — short cationic peptides that rupture microbial membranes by physics rather than by inhibiting a single enzyme. How human defensins and cathelicidins actually kill bacteria, why the polymyxin antibiotics already prove the mechanism works in the clinic, and why turning that mechanism into a marketable drug has been so much harder than the biology alone would suggest.
Innate-Immunity
-
Antimicrobial Peptides: The Innate Immune System's Own Antibiotics