The antimicrobial peptides lactoferricin B and magainin 2 cross over the bacterial cytoplasmic membrane and reside in the cytoplasm.
The localization of immunolabelled antimicrobial peptides was studied using transmission electron microscopy. Staphylococcus aureus and Escherichia coli were exposed to lactoferricin B (17-41), lactoferricin B (17-31) and D-lactoferricin B (17-31). E. coli was also exposed to cecropin P1 and magainin 2. The lactoferricins were found in the cytoplasm of both bacteria. In S. aureus the amount of cytoplasmic lactoferricin B (17-41) was time- and concentration-dependent, reaching a maximum within 30 min. Cecropin P1 was confined to the cell wall, while magainin 2 was found in the cytoplasm of E. coli. The finding of intracellularly localized magainin is not reported previously.
Haukland
H H
HH
Department of Medical Microbiology, University Hospital Tromsø, Norway. mlabhh@rito.no
Ulvatne
H
H
Sandvik
K
K
Vorland
L H
LH
D023181:Antimicrobial Cationic Peptides / Q000378:metabolism* / Q000494:pharmacology; D002462:Cell Membrane / Q000378:metabolism*; D003593:Cytoplasm / Q000378:metabolism; D004926:Escherichia coli / Q000187:drug effects / Q000378:metabolism*; D007150:Immunohistochemistry; D007781:Lactoferrin / Q000031:analogs & derivatives* / Q000378:metabolism* / Q000494:pharmacology; D054806:Magainins; D008826:Microbial Sensitivity Tests; D013211:Staphylococcus aureus / Q000187:drug effects / Q000378:metabolism*; D029867:Xenopus Proteins
D023181:Antimicrobial Cationic Peptides; D054806:Magainins; D029867:Xenopus Proteins; C053301:magainin 2 peptide, Xenopus; C082171:lactoferricin B; D007781:Lactoferrin