Inorganic mercury and cadmium induce rigidity in eukaryotic lipid extracts while mercury also ruptures red blood cells

Kerek, Evan; Hassanin, Mohamed; Prenner, Elmar J.

doi:10.1016/j.bbamem.2017.12.014

Cited by 23 publications

(16 citation statements)

References 49 publications

Supporting

Mentioning

Contrasting

Order By: Relevance

“…This result demonstrated that different metals interact with the lipids quite differently. Similar results have also been observed that different transition metals could direct the self-assembly of amphiphiles with different morphologies, and work has also been done on toxic metals with liposomes. − …”

Section: Resultssupporting

confidence: 62%

Cu²⁺-Directed Liposome Membrane Fusion, Positive-Stain Electron Microscopy, and Oxidation

Liu

2018

Langmuir

View full text Add to dashboard Cite

Natural lipid headgroups contain a few types of metal ligands, such as phosphate, amine, and serine, which interact with metal ions differently. Herein, we studied the binding between Cu and liposomes with four types of headgroups: phosphocholine (PC), phosphoglycerol (PG), phosphoserine (PS), and cholinephosphate (CP). Using fluorescently headgroup-labeled liposomes, Cu strongly quenched the CP and PS liposomes, whereas quenching of PC and PG was weaker. Dynamic light scattering indicated that all of the four liposomes aggregated at high Cu concentrations, and ethylenediaminetetraacetic acid (EDTA) only restored the original size of the PC liposome, implying fusion of the other three types of liposomes. The leakage tests revealed that the integrity of PC liposomes was not affected by Cu, but the other three liposomes leaked. Under TEM, all of the liposomes show a positive-stain feature in the presence of Cu and Cu-stained individual liposomes with a short incubation time (<1 min). The oxidative catalytic property of Cu was also tested, and a tight binding by the PS liposome inhibited the activity of Cu. Finally, a model of interaction for each liposome was proposed, and each one has a different metal-binding and interaction mechanism.

show abstract

Section: Resultssupporting

confidence: 62%

Cu²⁺-Directed Liposome Membrane Fusion, Positive-Stain Electron Microscopy, and Oxidation

Liu

2018

Langmuir

View full text Add to dashboard Cite

show abstract

“…Other divalent cations have been shown to associate strongly with PS lipids, such as Mg 2þ (22,76) and Cd 2þ (77), and are relevant either because of their physiological ubiquity or toxic effects. Interactions between PS lipids and many of these cations have been studied with FTIR and have been shown to be ion dependent.…”

Section: Discussionmentioning

confidence: 99%

Physiological Calcium Concentrations Slow Dynamics at the Lipid-Water Interface

Valentine

Cárdenas

Elber

et al. 2018

Biophysical Journal

View full text Add to dashboard Cite

Phospholipids can interact strongly with ions at physiological concentrations, and these interactions can alter membrane properties. Here, we describe the effects of calcium ions on the dynamics in phospholipid membranes. We used a combination of time-resolved ultrafast two-dimensional infrared spectroscopy and molecular dynamics simulations. We found that millimolar Ca 2þ concentrations lead to slower fluctuations in the local environment at the lipid-water interface of membranes with phosphatidylserine. The effect was only observed in bilayers containing anionic phosphatidylserine; membranes composed of only zwitterionic phosphatidylcholine did not experience a slowdown. Local water dynamics were measured using the ester groups as label-free probes and were found to be up to 50% slower with 2.5 mM Ca 2þ . Molecular dynamics simulations show that Ca 2þ primarily binds to the carboxylate group of phosphatidylserines. These findings have implications for apoptotic and diseased cells in which phosphatidylserine is exposed to extracellular calcium and for the biophysical effects of divalent cations on lipid bilayers.

show abstract

“…To quantitatively evaluate the Laurdan emission spectra data, the membrane fluidity at different concentrations of the PFCs or other surfactants was expressed by generalized polarization GP = ( I 440 – I 490 )/( I 440 + I 490 ), where I 440 and I 490 are the emission intensities at these two wavelengths, respectively. 36 A larger GP value corresponds to lower membrane fluidity. As shown in Figure 6 , the surfactants with a larger GP value change are more potent in fluidizing the membrane.…”

Section: Results and Discussionmentioning

confidence: 99%

Stabilization of Liposomes by Perfluorinated Compounds

et al. 2018

View full text Add to dashboard Cite

Perfluorinated compounds (PFCs) are emerging persistent environmental contaminants that may be toxic to animals and humans. To gain fundamental insights into the mechanism of their toxicity, the interactions of phosphocholine (PC) liposomes as model membranes were studied with three types of PFCs, including perfluorooctanoic acid, perfluorooctane sulfonate, and perfluorohexanesulfonic acid potassium salt, together with three common surfactants: sodium dodecyl sulfate (SDS), cetyltrimethylammonium bromide (CTAB), and sodium 1-heptanesulfonate (SHS). The interactions were systematically characterized by zeta potential measurement, dynamic light scattering, negative-stain transmission electron microscopy, and fluorescence spectroscopy. Unmodified liposomes, calcein-loaded liposomes, and Laurdan dye-embedded liposomes were all tested. By gradually increasing the temperature, the three PFCs and SHS decreased the leakage of calcein-loaded 1,2-dipalmitoyl-sn-glycero-3-phosphocholine liposomes, whereas SDS and CTAB increased the leakage. The PFCs that affected the lipid membranes stronger than SHS were attributable to their perfluoroalkyl carbon chains. Packing of the lipids was further studied using Laurdan dye as a probe. Calcein leakage tests also indicated that PFCs inhibited lipid membrane leakage induced by inorganic nanoparticles such as silica and gold nanoparticles. This study confirmed the similar effect of the PFCs as cholesterol in affecting membrane properties and would be helpful for understanding the interaction mechanism of PFCs and cell membranes.

show abstract

Inorganic mercury and cadmium induce rigidity in eukaryotic lipid extracts while mercury also ruptures red blood cells

Cited by 23 publications

References 49 publications

Cu²⁺-Directed Liposome Membrane Fusion, Positive-Stain Electron Microscopy, and Oxidation

Cu²⁺-Directed Liposome Membrane Fusion, Positive-Stain Electron Microscopy, and Oxidation

Physiological Calcium Concentrations Slow Dynamics at the Lipid-Water Interface

Stabilization of Liposomes by Perfluorinated Compounds

Contact Info

Product

Resources

About

Inorganic mercury and cadmium induce rigidity in eukaryotic lipid extracts while mercury also ruptures red blood cells

Cited by 23 publications

References 49 publications

Cu2+-Directed Liposome Membrane Fusion, Positive-Stain Electron Microscopy, and Oxidation

Cu2+-Directed Liposome Membrane Fusion, Positive-Stain Electron Microscopy, and Oxidation

Physiological Calcium Concentrations Slow Dynamics at the Lipid-Water Interface

Stabilization of Liposomes by Perfluorinated Compounds

Contact Info

Product

Resources

About

Cu²⁺-Directed Liposome Membrane Fusion, Positive-Stain Electron Microscopy, and Oxidation

Cu²⁺-Directed Liposome Membrane Fusion, Positive-Stain Electron Microscopy, and Oxidation