The human cathelicidin peptide LL-37 and truncated variants induce segregation of lipids and proteins in the plasma membrane of Candida albicans.
The human cathelicidin peptide LL-37 and several truncated variants differ in their capability to transmigrate over the plasma membrane of Candida albicans. We investigated whether retention at the cell perimeter or membrane transmigration affects their membrane-disrupting activities and candidacidal properties. Using fluorescein-labeled peptides, we demonstrate that LL-37 and its C-terminally truncated peptide LL-31 remain permanently associated with the perimeter of the cell. The N-terminally truncated peptide RK-31 initially accumulated at the cell boundary, but transmigrated into the cytoplasm within 30 min. The C-terminally truncated peptide LL-25 transmigrated instantaneously into the cytoplasm. The ultrastructural effects on the plasma membrane were studied by freeze-fracture electron microscopy combined with filipin cytochemistry. All peptides, whether they transmigrated over the plasma membrane or not, induced phase separation in the plasma membrane. All peptides induced leakage of cell components, including nucleotides and proteins. Proteins were identified by SDS-PAGE in combination with mass spectrometry, which revealed that predominantly proteins smaller than 50 kDa had leaked out of C. albicans.
den Hertog
Alice L
AL
Department of Oral Biochemistry, Academic Centre for Dentistry Amsterdam, Free University and University of Amsterdam, Van der Boechorststraat 7, NL-1081 BT Amsterdam, The Netherlands.
van Marle
Jan
J
Veerman
Enno C I
EC
Valentijn-Benz
Marianne
M
Nazmi
Kamran
K
Kalay
Hakan
H
Grün
Christian H
CH
Van't Hof
Wim
W
Bolscher
Jan G M
JG
Nieuw Amerongen
Arie V
AV
D000595:Amino Acid Sequence; D023181:Antimicrobial Cationic Peptides / Q000737:chemistry / Q000235:genetics / Q000378:metabolism*; D002176:Candida albicans / Q000378:metabolism* / Q000648:ultrastructure; D002462:Cell Membrane / Q000378:metabolism* / Q000648:ultrastructure; D002463:Cell Membrane Permeability; D014644:Genetic Variation / Q000235:genetics*; D006801:Humans; D050356:Lipid Metabolism; D046529:Microscopy, Electron, Transmission; D008969:Molecular Sequence Data; D009711:Nucleotides / Q000378:metabolism; D016415:Sequence Alignment; D054804:Cathelicidins
D023181:Antimicrobial Cationic Peptides; D009711:Nucleotides; D054804:Cathelicidins