Calcium ions induce collapse of charged O-side chains of lipopolysaccharides from Pseudomonas aeruginosa
| Autor: | Emanuel Schneck, Terry J. Beveridge, Bonnie Quinn, Motomu Tanaka, David A. Pink, Oleg Konovalov, Erzsebet Papp-Szabo |
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| Jazyk: | angličtina |
| Rok vydání: | 2009 |
| Předmět: |
Ions
Lipopolysaccharides Electron density Strain (chemistry) Biomedical Engineering Biophysics Molecular Conformation chemistry.chemical_element Bioengineering Articles Calcium Biochemistry Ion Biomaterials Crystallography Membrane chemistry X-Ray Diffraction Monolayer Pseudomonas aeruginosa Side chain Molecule Biotechnology |
| Popis: | Lipopolysaccharide (LPS) monolayers deposited on planar, hydrophobic substrates were used as a defined model of outer membranes of Pseudomonas aeruginosa strain dps 89. To investigate the influence of ions on the (out-of-plane) monolayer structure, we measured specular X-ray reflectivity at high energy (22 keV) to ensure transmission through water. Electron density profiles were reconstructed from the reflectivity curves, and they indicate that the presence of Ca 2+ ions induces a significant change in the conformation of the charged polysaccharide head groups (O-side chains). Monte Carlo simulations based on a minimal computer model of LPS molecules allow for the modelling of 100 or more molecules over 10 −3 s and theoretically explained the tendency found by experiments. |
| Databáze: | OpenAIRE |
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