The dynamics of the surface layer of lipid membranes doped by vanadium complex: computer modeling and EPR studies

Olchawa, Ryszard; Man, Dariusz; Pytel, B

doi:10.1515/nuka-2015-0070

Cited by 4 publications

(2 citation statements)

References 11 publications

Supporting

Mentioning

Contrasting

Order By: Relevance

“…Liposomes are susceptible to the biologically active substances [8,9]. The best method of the membrane fluidity study is the EPR technique [10][11][12], because, it permits to investigate the membrane fluidity in transverse section [13,14]. …”

Section: Introductionmentioning

confidence: 99%

Impact of Vanadium(IV)-Oxy Acetylacetonate and Vanadium(III) Acetylacetonatel on the DPPC Liposome Membranes: EPR Studies

et al. 2017

View full text Add to dashboard Cite

The effect of vanadium (IV)-oxy acetylacetonate (V4) and vanadium(III) acetylacetonate (V3) on the liposome membranes formed of synthetic lecithin (DPPC) was presented in this paper. Liposomes were formed during the sonication of DPPC lecithin in an aqueous medium. The concentration of the vanadium compounds changed in the range of 0% to 2.4% in molar ratio to the lecithin. The EPR technique made use of three spin probes penetrating the different areas of the membrane (as follows: TEMPO, 16-DOXYL stearic acid methyl ester, stearic acid 5-DOXYL methyl ester). TEMPO probe penetrates the interphase water-lipid (partition parameter F ), the probe 16-DOXYL locates in the middle of the lipid bilayer (rotational correlation time τ ), the probe 5-DOXYL gives a picture of membrane fluidity (the order parameter) just below the polar head groups. The results of our research showed the following conclusions. The change of membrane fluidity, as a function of admixture concentration, was dependent on the type of additives. TEMPO probe recorded an increase in liquidity interphase water-lipid for both admixtures: V3 and V4. 16-DOXYL probe indicated that the admixture V3 increases the fluidity in the center of the lipid bilayer. Admixture V4 significantly less impacted on the change of the membrane middle. The 5-DOXYL probe did not influence on the membrane surface portion, there were not observed significant changes under the impact of admixtures. V3 showed stronger impact on membrane fluidity.

show abstract

Section: Introductionmentioning

confidence: 99%

Impact of Vanadium(IV)-Oxy Acetylacetonate and Vanadium(III) Acetylacetonatel on the DPPC Liposome Membranes: EPR Studies

et al. 2017

View full text Add to dashboard Cite

show abstract

“…Electron paramagnetic resonance (EPR) is a technique used to investigate membrane fluidity impacted by biologically active substances through the spin probe method [1][2][3]. Due to diamagnetic properties of biological structures the spin probe method is suitable for EPR spectroscopy [4][5][6]. The structure of the liposomes resembles biological membranes, therefore they are used as model membranes in many experiments [3,7].…”

Section: Introductionmentioning

confidence: 99%

Impact of Plesiomonas Shigelloides Strain CNCTC 144/92 Lipopolysaccharide on DPPC Liposome Membranes: EPR Method

2017

View full text Add to dashboard Cite

Membrane fluidity measurements were performed for synthetic DPPC liposomes sonicated in aqueous solution and doped by Plesiomonas shigelloides strain CNCTC 144/92 (serotype O74:H5) lipopolysaccharide (LPS) extracted from the phenol (LPS PhOH) and water (LPSH 2 O) phases. Concentrations of LPS in relation to DPPC ranged from 0 to 1.4% (molar ratio). The EPR spin probe method was used to describe physicochemical properties of different regions of the lipid bilayer. Since TEMPO spin probe dissolves both in the hydrophobic region of the membrane and in an aquatic environment it is possible to determine the spectroscopic partition parameter F , indicating the changes that occur in the water-lipid interface. The 16-DOXYL probe distributed in the middle of the lipid bilayer makes it possible to obtain the rotational correlation time τ parameter, which provides information about fluidity changes in the liposome membrane. Here we report that increasing concentrations (mainly in the range of 0.4-0.8%) of investigated LPS PhOH and LPSH 2 O significantly influence spectroscopic parameters (F and τ). The surface area of the DPPC liposomes membranes was affected predominantly by LPSH 2 O while the lipid bilayer was most influenced by LPS PhOH .

show abstract

Concentration dependence of nitroxyl spin probes in liposomal solution: electron spin resonance and overhauser-enhanced magnetic resonance studies

Meenakumari¹,

Utsumi

Jawahar³

et al. 2016

Journal of Liposome Research

View full text Add to dashboard Cite

In this work, the detailed studies of electron spin resonance (ESR) and overhauser-enhanced magnetic resonance imaging (OMRI) were carried out for permeable nitroxyl spin probe, MC-PROXYL as a function of agent concentration in liposomal solution. In order to compare the impermeable nature of nitroxyl radical, the study was also carried out only at 2 mM concentration of carboxy-PROXYL. The ESR parameters were estimated using L-band and 300 MHz ESR spectrometers. The line width broadening was measured as a function of agent concentration in liposomal solution. The estimated rotational correlation time is proportional to the agent concentration, which indicates that less mobile nature of nitroxyl spin probe in liposomal solution. The partition parameter and permeability values indicate that the diffusion of nitroxyl spin probe distribution into the lipid phase is maximum at 2 mM concentration of MC-PROXYL. The dynamic nuclear polarization (DNP) parameters such as DNP factor, longitudinal relaxivity, saturation parameter, leakage factor and coupling factor were estimated for 2 mM MC-PROXYL in 400 mM liposomal dispersion. The spin lattice relaxation time was shortened in liposomal solution, which leads to the high relaxivity. Reduction in coupling factor is due to less interaction between the electron and nuclear spins, which causes the reduction in enhancement. The leakage factor increases with increasing agent concentration. The increase in DNP enhancement was significant up to 2 mM in liposomal solution. These results paves the way for choosing optimum agent concentration and OMRI scan parameters used in intra and extra membrane water by loading the liposome vesicles with a lipid permeable nitroxyl spin probes in OMRI experiments.

show abstract

The dynamics of the surface layer of lipid membranes doped by vanadium complex: computer modeling and EPR studies

Cited by 4 publications

References 11 publications

Impact of Vanadium(IV)-Oxy Acetylacetonate and Vanadium(III) Acetylacetonatel on the DPPC Liposome Membranes: EPR Studies

Impact of Vanadium(IV)-Oxy Acetylacetonate and Vanadium(III) Acetylacetonatel on the DPPC Liposome Membranes: EPR Studies

Impact of Plesiomonas Shigelloides Strain CNCTC 144/92 Lipopolysaccharide on DPPC Liposome Membranes: EPR Method

Concentration dependence of nitroxyl spin probes in liposomal solution: electron spin resonance and overhauser-enhanced magnetic resonance studies

Contact Info

Product

Resources

About