Effects of human lactoferrin on the cytoplasmic membrane of Candida albicans cells related with its candidacidal activity.
Human lactoferrin is an innate host defence protein with antimicrobial activity that exerts a candidacidal effect in a cation concentration-dependent manner. We investigated the ability of this cationic protein (with an isoelectric point of 8.7) to permeabilize the cytoplasmic membrane of Candida albicans cells. Despite minor K(+)-release in lactoferrin-treated C. albicans cells, the killing effect was not related to an extensive membrane permeabilization, as indicated by: (a) the non-release of macromolecular cytosolic constituents; (b) the non-permeabilization for extracellular propidium iodide nor for intracellular accumulated calcein; and (c) the inability to disrupt the phospholipid bilayer of 8-aminonaphthalene-1,3,6, trisulfonic acid/p-xylene-bis-pyridiniumbromide-loaded liposomes. These results suggest that lactoferrin exerts its candidacidal effect through a mechanism different from membrane permeabilization described for other cationic peptides.
Viejo-Díaz
Mónica
M
Department of Functional Biology (Microbiology), Faculty of Medicine, University of Oviedo, C/Julian Claveria, 6, 33006 Oviedo, Asturias, Spain.
Andrés
María T
MT
Fierro
José F
JF
D000935:Antifungal Agents / Q000494:pharmacology*; D023181:Antimicrobial Cationic Peptides / Q000494:pharmacology; D002176:Candida albicans / Q000187:drug effects*; D002462:Cell Membrane / Q000187:drug effects* / Q000502:physiology; D002463:Cell Membrane Permeability / Q000187:drug effects; D006801:Humans; D007781:Lactoferrin / Q000502:physiology*; D008826:Microbial Sensitivity Tests / Q000379:methods; D011188:Potassium / Q000378:metabolism
D000935:Antifungal Agents; D023181:Antimicrobial Cationic Peptides; D007781:Lactoferrin; D011188:Potassium