Permeation of bacterial cells, permeation of cytoplasmic and artificial membrane vesicles, and channel formation on lipid bilayers by peptide antibiotic AS-48.
Peptide AS-48 induces ion permeation, which is accompanied by the collapse of the cytoplasmic membrane potential, in sensitive bacteria. Active transport by cytoplasmic membrane vesicles is also impaired by AS-48. At low concentrations, this peptide also causes permeability of liposomes to low-molecular-weight compounds without a requirement for a membrane potential. Higher antibiotic concentrations induce severe disorganization, which is visualized under electron microscopy as aggregation and formation of multilamellar structures. Electrical measurements suggest that AS-48 can form channels in lipid bilayers.
Departamento de Microbiologia, Facultad de Ciencias, Universidad de Granada, Spain.
A
A
Gálvez
M
M
Maqueda
M
M
Martínez-Bueno
E
E
Valdivia
D000900:Anti-Bacterial Agents / Q000494:pharmacology*; D001426:Bacterial Proteins; D001692:Biological Transport / Q000187:drug effects; D002462:Cell Membrane / Q000187:drug effects / Q000502:physiology; D002463:Cell Membrane Permeability / Q000187:drug effects; D003593:Cytoplasm / Q000187:drug effects / Q000502:physiology; D013293:Enterococcus faecalis / Q000187:drug effects / Q000502:physiology*; D005615:Freezing; D007473:Ion Channels / Q000502:physiology*; D007700:Kinetics; D008051:Lipid Bilayers; D008564:Membrane Potentials / Q000187:drug effects; D008954:Models, Biological; D010455:Peptides / Q000737:chemistry / Q000494:pharmacology; D010713:Phosphatidylcholines; D010743:Phospholipids; D012413:Rubidium / Q000378:metabolism
D000900:Anti-Bacterial Agents; D001426:Bacterial Proteins; D007473:Ion Channels; D008051:Lipid Bilayers; D010455:Peptides; D010713:Phosphatidylcholines; D010743:Phospholipids; C051034:BacA protein, Enterococcus faecalis; C024990:asolectin; D012413:Rubidium