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J Membr Biol

Title:		"The bacterial peptide pheromone plantaricin A permeabilizes cancerous, but not normal, rat pituitary cells and differentiates between the outer and inner membrane leaflet"
Author(s):		Sand SL; Haug TM; Nissen-Meyer J; Sand O;
Address:		"Department of Molecular Biosciences, University of Oslo, NO 0316, Oslo, Norway"
Journal Title:		J Membr Biol
Year:		2007
Volume:		20070717
Issue:		2-Mar
Page Number:		61 - 71
DOI:		10.1007/s00232-007-9030-3
ISSN/ISBN:		0022-2631 (Print) 0022-2631 (Linking)
Abstract:		"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 microM 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 microM 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 [Ca(2+)](i) and cytosolic concentration of fluorochrome verified the rapid permeabilizing effect of PlnA on cancerous cells and the insensitivity of normal pituitary cells"
Keywords:		Animals Bacteriocins/*pharmacology Cell Membrane/drug effects/ultrastructure Cell Membrane Permeability/*drug effects Cytophotometry Fura-2 Patch-Clamp Techniques Pituitary Gland/*drug effects Pituitary Neoplasms Rats;
Notes:		"MedlineSand, Sverre L Haug, Trude M Nissen-Meyer, Jon Sand, Olav eng Research Support, Non-U.S. Gov't 2007/07/20 J Membr Biol. 2007 Apr; 216(2-3):61-71. doi: 10.1007/s00232-007-9030-3. Epub 2007 Jul 17"