Antigonococcal activity of human neutrophil cathepsin G.
We have shown that lysosomal cathepsin G, prepared from acid extracts of granules derived from human polymorphonuclear granulocytes, exhibits potent in vitro antimicrobial activity against Neisseria gonorrhoeae. An isolated isozyme of cathepsin G was found to exhibit antigonococcal activity by a nonenzymatic mechanism in a time-dependent manner. Moreover, we observed that the antigonococcal activity of cathepsin G was relatively independent of pH and evident over a pH range resembling that invoked for maturing phagolysosomes. Using a number of isogenic strains, we determined that certain mutations known to alter cell envelope structure rendered gonococci more susceptible to cathepsin G. This suggests that the susceptibility of gonococci to cathepsin G, and possibly other antimicrobial proteins derived from PMN granules, is genetically determined and possibly related to the structure of the gonococcal cell envelope.
D023181:Antimicrobial Cationic Peptides; D001425:Bacterial Outer Membrane Proteins / Q000502:physiology; D001770:Blood Bactericidal Activity; D001798:Blood Proteins / Q000502:physiology; D056649:Cathepsin G; D002403:Cathepsins / Q000037:antagonists & inhibitors / Q000302:isolation & purification / Q000502:physiology*; D006801:Humans; D007526:Isoelectric Point; D007527:Isoenzymes / Q000502:physiology; D008247:Lysosomes / Q000201:enzymology; D008565:Membrane Proteins; D009344:Neisseria gonorrhoeae / Q000502:physiology*; D009504:Neutrophils / Q000502:physiology*; D010403:Penicillin Resistance; D012697:Serine Endopeptidases
D023181:Antimicrobial Cationic Peptides; D001425:Bacterial Outer Membrane Proteins; D001798:Blood Proteins; D007527:Isoenzymes; D008565:Membrane Proteins; C021623:bactericidal permeability increasing protein; D002403:Cathepsins; D012697:Serine Endopeptidases; C534094:CTSG protein, human; D056649:Cathepsin G