Changes in the composition of anionic membrane phospholipids influence protein secretion and cell envelope biogenesis in Escherichia coli

Anisimova, E. V.; Badyakina, A. O.; Vasileva, N.; Nesmeyanova, M. A.

doi:10.1007/s11021-005-0044-5

Cited by 2 publications

(2 citation statements)

References 15 publications

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“…43 The positively charged magainin 2 molecules tend to target anionic lipids in the cell membrane via electrostatic attraction. E. coli cell membranes only contain about 32% anionic lipids; 44 thus, a purely negatively charged lipid bilayer should require a lower peptide concentration for disruption than the MIC. In this set of experiments, we employed anionic POPG lipids to represent the bacterial cell membrane, and therefore, a lower concentration of 800 nM of magainin 2 was believed to be sufficient to ensure effective interactions between magainin 2 and the POPG/POPG bilayer.…”

Section: Resultsmentioning

confidence: 99%

Molecular Interactions between Magainin 2 and Model Membranes in Situ

et al. 2009

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In this paper, we investigated the molecular interactions of Magainin 2 with model cell membranes using Sum Frequency Generation (SFG) vibrational spectroscopy and Attenuated Total Reflectance -Fourier Transform Infrared spectroscopy (ATR-FTIR). Symmetric 1-Palmitoyl-2-Oleoyl-snGlycero-3-[Phospho-rac-(1-glycerol)] (POPG) and 1-Palmitoyl-2-Oleoyl-sn-Glycero-3-Phosphocholine (POPC) bilayers, which model the bacterial and mammalian cell membranes respectively, were used in the studies. It was observed by SFG that Magainin 2 orients relatively parallel to the POPG lipid bilayer surface at low solution concentrations, around 200 nM. When increasing the Magainin 2 concentration to 800 nM, both SFG and ATR-FTIR results indicate that Magainin 2 molecules insert into the POPG bilayer and adopt a transmembrane orientation with an angle of about 20 degrees from the POPG bilayer normal. For the POPC bilayer, even at a much higher peptide concentration of 2.0 µM, no ATR-FTIR signal was detected. For this concentration on POPC, SFG studies indicated that Magainin 2 molecules adopt an orientation nearly parallel to the bilayer surface, with an orientation angle of 75 degrees from the surface normal. This shows that SFG has a much better detection limit than ATR-FTIR and can therefore be applied to study interfacial molecules with much lower surface coverage. This Magainin 2 orientation study and further investigation of the lipid bilayer SFG signals support the proposed toroidal pore model for the antimicrobial activity of Magainin 2.

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Section: Resultsmentioning

confidence: 99%

Molecular Interactions between Magainin 2 and Model Membranes in Situ

et al. 2009

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“…It was shown that, depending on its dose, CL forms domains in the bacterial membrane, no domains are formed at low CL concentrations [8]. It was found that CL is involved in Bacillus subtilis osmotic adaptation [10] and in secretion of E. coli enzymes [2]. Changes in the localization of fl uorescent label-bound CL sporulation process were de mon strated for E. coli [11] and a signifi cant increase in CL content in spores was shown for Bacillus subtilis [9].…”

Section: Resultsmentioning

confidence: 99%

Effects of Liposomes of Different Lipid Composition on In Vitro Growth of Mycobacterium Tuberculosis H37Rv

et al. 2009

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The growth of M. tuberculosis H37RV in culture medium was studied after addition of liposomes from different lipids (phosphatidylcholine, cardiolipin, and glycosphyngolipids). Addition of phosphatidylcholine into culture medium did not modify the growth and multiplication of mycobacteria. Addition of glycosphyngolipids and their mixture with phosphatidylcholine partially inhibited the growth. Addition of cardiolipin inhibited the growth of mycobacteria and even suppressed it, depending on the dose. Presumably, high concentrations of cardiolipin added into the culture medium, can transfer the mycobacteria into an uncultivable state.

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Changes in the composition of anionic membrane phospholipids influence protein secretion and cell envelope biogenesis in Escherichia coli

Cited by 2 publications

References 15 publications

Molecular Interactions between Magainin 2 and Model Membranes in Situ

Molecular Interactions between Magainin 2 and Model Membranes in Situ

Effects of Liposomes of Different Lipid Composition on In Vitro Growth of Mycobacterium Tuberculosis H37Rv

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