The Bacterial Peptide Pheromone Plantaricin A Permeabilizes Cancerous, but not Normal, Rat Pituitary Cells and Differentiates between the Outer and Inner Membrane Leaflet
| Autor: | Jon Nissen-Meyer, Olav Sand, Trude M. Haug, Sverre L. Sand |
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| Rok vydání: | 2007 |
| Předmět: |
Cell Membrane Permeability
Patch-Clamp Techniques Physiology Biophysics Peptide Bacteriocins Anterior pituitary medicine Animals Inner membrane Pituitary Neoplasms Patch clamp chemistry.chemical_classification biology Cell Membrane Cell Biology biology.organism_classification Rats Cytosol medicine.anatomical_structure Membrane Biochemistry chemistry Pituitary Gland Cytophotometry Fura-2 Antibacterial activity Lactobacillus plantarum |
| Zdroj: | Journal of Membrane Biology. 216:61-71 |
| ISSN: | 1432-1424 0022-2631 |
| DOI: | 10.1007/s00232-007-9030-3 |
| Popis: | Plantaricin A (PlnA) is a 26-mer peptide pheromone with membrane-permeabilizing, strain-specific antibacterial activity, produced by Lactobacillus plantarum C11. We investigated the membrane-permeabilizing effects of PlnA on cultured cancerous and normal rat anterior pituitary cells using patch-clamp techniques and microfluorometry (fura-2). Cancerous cells displayed massive permeabilization within 5 s after exposure to 10–100 μm PlnA. The membrane depolarized to nearly 0 mV, and the membrane resistance decreased to a mere fraction of the initial value after less than 1 min. In outside-out membrane patches, 10 μm PlnA induced membrane currents reversing at 0 mV, which is compatible with an unspecific conductance increase. The d and l forms of the peptide had similar potency, indicating a nonchiral mechanism for the membrane-permeabilizing effect. Surprisingly, inside-out patches were insensitive to 1 mm PlnA. Primary cultures of normal rat anterior pituitary cells were also insensitive to the peptide. Thus, PlnA differentiates between plasma membranes and membrane leaflets. Microfluorometric recordings of [Ca2+] i and cytosolic concentration of fluorochrome verified the rapid permeabilizing effect of PlnA on cancerous cells and the insensitivity of normal pituitary cells. |
| Databáze: | OpenAIRE |
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