Journal Article

PreJuSER-11530

http://join2-wiki.gsi.de/foswiki/pub/Main/Artwork/join2_logo100x88.png Characterization of Liposomes Formed by Lipopolysaccharides from Burkholderia Cenocepacia, Burkholderia Multivorans und Agrobacterium Tumefaciens: from the Molecular Structure to the Aggregate Architecture

d'Errico, G. ; Silipo, A. ; Mangiapia, G. ; Vitiello, G. ; Radulescu, A.FZJ* ; Molinaro, A. ; Lanzetta, R. ; Paduano, L.

2010
RSC Publ. Cambridge

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Please use a persistent id in citations: doi:10.1039/c0cp00066c

Abstract: The microstructure of liposomes formed by the lipopolysaccharides (LPS) derived from Burkholderia cenocepacia ET-12 type strain LMG 16656, Burkholderia multivorans strain C1576 and Agrobacterium tumefaciens strain TT111 has been investigated by a combined experimental strategy, including dynamic light scattering (DLS), small-angle neutron scattering (SANS) and electron paramagnetic resonance (EPR). The results highlight that the LPS molecular structure determines, through a complex interplay of hydrophobic, steric and electrostatic interactions, the morphology of the aggregates formed in aqueous medium. All the considered LPS form liposomes that in most cases present a multilamellar arrangement. The thickness of the hydrophobic domain of each bilayer and the local ordering of the acyl chains are determined not only by the molecular structure of the LPS glycolipid portion (lipid A), but also, indirectly, by the bulkiness of the saccharidic portion. In the case of a long polysaccharidic chain, such as that of the LPS derived from Burkholderia multivorans, liposomes coexist with elongated micellar aggregates, whose population decreases if a typical phospholipid, such as dioleoyl phosphatidylethanolamine (DOPE) is introduced in the liposome formulation. The effect of temperature has also been considered: for all the considered LPS an extremely smooth transition of the acyl chain self-organization from a gel to a liquid crystalline phase is detected around 30-35 °C. In the biological context, our results suggest that the rich biodiversity of LPS molecular structure could be fundamental to finely tune the structure and functional properties of the outer membrane of Gram negative bacteria.

Keyword(s): Agrobacterium tumefaciens: metabolism (MeSH) ; Burkholderia: metabolism (MeSH) ; Burkholderia cenocepacia: metabolism (MeSH) ; Electron Spin Resonance Spectroscopy (MeSH) ; Light (MeSH) ; Lipopolysaccharides: chemistry (MeSH) ; Liposomes: chemistry (MeSH) ; Neutron Diffraction (MeSH) ; Phosphatidylethanolamines: chemistry (MeSH) ; Scattering, Radiation (MeSH) ; Scattering, Small Angle (MeSH) ; 1,2-dioleoyl-glycero-3-phosphatidyl ethanolamine ; Lipopolysaccharides ; Liposomes ; Phosphatidylethanolamines ; J

Note: The authors thank CSGI (Consorzio Interuniversitario per lo sviluppo dei Sistemi a Grande Interfase) and MIUR (PRIN 2007) for financial support. B. multivorans cells were kindly furnished by Dr Paola Cescutti (Universita di Trieste), B. cenocepacia cells were kindly furnished by Dr Anthony De-Soyza (University of Newcastle) and R-LPS from A. tumefaciens was a kind gift from Dr Cristina De Castro (Universita di Napoli). Forschungszentrum Julich is acknowledged for provision of beam time. SANS experiments were supported by the European Commission, NMI3 contract RII3-CT-2003-505925. The authors thank Prof. Lucia Costantino for her helpful comments. Finally, we thank the referees whose comments helped improve the manuscript.

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Contributing Institute(s):

1. Streumethoden (IFF-4)
2. Neutronenstreuung (IFF-5)
3. JCNS (Jülich Centre for Neutron Science JCNS (JCNS) ; JCNS)

Research Program(s):

1. Großgeräte für die Forschung mit Photonen, Neutronen und Ionen (PNI) (P55)
2. BioSoft: Makromolekulare Systeme und biologische Informationsverarbeitung (P45)

Experiment(s):

1. KWS-2: Small angle scattering diffractometer (NL3ao)

Appears in the scientific report 2010

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Database coverage:
; JCR ; Science Citation Index Expanded ; Thomson Reuters Master Journal List ; Web of Science Core Collection

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