Abstract
Lipodepsipeptides (LPDs) are a group of cyclic, acylated peptides produced by several Pseudomonas species. They are usually divided in two groups, mycins and peptins, on the basis of the size of the amino acidic part of the molecule. Mycins have a ring of 9 amino acids closed between the first and the last residue, peptins contain a more complex peptide moiety of up to 25 amino acids, partially cyclized. Both mycins and peptins attack the plasma membrane, but may have different target organisms. Comparing the mode of action of these two classes of LDPs on natural and model membranes we observed that all peptides induced red blood cell haemolysis and leakage of tonoplasts and liposornes by the formation of pores. The haemolytic activity of the smaller mycins was higher than that of the bigger peptins and proportional to the amphipathic index of the molecule. The extent of permeabilization was dependent also on the composition of the lipid membrane. In particular, mycins show a preference for sterols, whereas peptins are more active on phospholipids, especially sphingomyelin. These differences may have physiological implications. The formation of discrete ion channels, with anionic selectivity, was directly demonstrated by electrophysiological experiments performed on planar lipid bilayers or sugar beet vacuoles. The channels show sub-states and their properties in vacuoles and in planar lipid membranes were remarkably similar.
Original language | English |
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Title of host publication | Pseudomonas syringae and related pathogens |
Subtitle of host publication | biology and genetic |
Editors | Nicola Sante Iacobellis, Alan Collmer, Steven W. Hutcheson, John W. Mansfield, Cindy E. Morris, Jesus Murillo, Norman W. Schaad, David E. Stead, Giuseppe Surico, Matthias S. Ullrich |
Place of Publication | Dordrecht |
Publisher | Springer |
Pages | 185-198 |
Number of pages | 14 |
ISBN (Electronic) | 9789401701334 |
ISBN (Print) | 9781402012273, 9789048162673 |
DOIs | |
Publication status | Published - 2003 |
Externally published | Yes |
Event | 6th International Conference on Pseudomonas Syringae Pathovars and Related Pathogens - Maratea, Italy Duration: 15 Sep 2002 → 19 Sep 2002 Conference number: 6 |
Conference
Conference | 6th International Conference on Pseudomonas Syringae Pathovars and Related Pathogens |
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Country/Territory | Italy |
City | Maratea |
Period | 15/09/02 → 19/09/02 |
Keywords
- Haemolysis
- Toxin pores
- Surface activity
- Lipid bilayer