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1
Content available remote The dynamics of the surface layer of lipid membranes doped by vanadium complex: computer modeling and EPR studies
100%
Olchawa R. , Man D. , Pytel B.
Nukleonika
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2015
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tom 60
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nr 3
395-398
EN
Penetration of the liposome membranes doped with vanadium complex formed in the liquid-crystalline phase from egg yolk lecithin (EYL) by the TEMPO (2,2,6,6-tetramethylpiperidine-1-oxyl) spin probes has been investigated. The penetration process was followed by 360 hours at 24°C, using the electron spin resonance (EPR) method. The spectroscopic parameter of the partition (F) of this probe indicated that a maximum rigidity of the membrane was at 3% concentration of the vanadium complex. Computer simulations showed that the increase in the rigidity of the membrane corresponds to the closure of gaps in the surface layer of the membrane, and indicates the essential role of the membrane surface in transport processes.
2
Content available The dynamics of the surface layer of lipid membranes doped by vanadium complex : computer modeling and EPR studies
100%
Olchawa R. , Man D. , Pytel B.
Nukleonika
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2015
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tom Vol. 60, No. 3, part 1
395--398
EN
Penetration of the liposome membranes doped with vanadium complex formed in the liquid-crystalline phase from egg yolk lecithin (EYL) by the TEMPO (2,2,6,6-tetramethylpiperidine-1-oxyl) spin probes has been investigated. The penetration process was followed by 360 hours at 24◦C, using the electron spin resonance (EPR) method. The spectroscopic parameter of the partition (F) of this probe indicated that a maximum rigidity of the membrane was at 3% concentration of the vanadium complex. Computer simulations showed that the increase in the rigidity of the membrane corresponds to the closure of gaps in the surface layer of the membrane, and indicates the essential role of the membrane surface in transport processes.
3
No increase of phosphatidylserine exposure accompanying the increased membrane fluidity in erythrocytes of ataxia telangiectasia gene [ATM] carriers
100%
Rybczynska M. , Kaczmarek J. , Pawlak A. L.
Cellular and Molecular Biology Letters
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1998
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tom 03
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nr 2
4
Protective action of cholesterol against changes in membrane fluidity induced by malathion
100%
Blasiak J. , Walter Z.
Acta Biochimica Polonica
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1992
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tom 39
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nr 1
5
The role of membrane fluidity in regulation of molecular mechanism of the xanthophyll cycle
88%
Strzalka K. , Latowski D. , Burda K.
Polish Journal of Natural Sciences. Supplement
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2003
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tom 01
6
Membrane fluidity as affected by the organophosphorus insecticide menthylbromfenvinfos
75%
Blasiak J.
Polish Journal of Environmental Studies
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1996
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tom 05
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nr 1
EN
The interaction of methylbromfenvinfos with model and native membranes was investigated using fluorescence anisotropy of 1,6-diphenyl-1,3,5-hexatriene (DPH), a probe located in the hydrophobic core of the bilayer and l,3-bis-(l-pyrene) propane, a probe distributed in the outer region of the bilayer. DPH reported a broadening of the transition profile and solidifying effects in the fluid phase of liposomes formed from dimyristoyl (DMPC), dipalmitoyl (DPPC), and distearoyl (DSPC) phosphatidylcholine in the presence of 50 μM of the insecticide. Py(3)Py detected an ordering effect of the insecticide in the fluid state of the lipids and abolished pretransition in DPPC and DSPC vesicles. Cholesterol added to DMPC decreased the influence of the insecticide. The effect of methylbromfenvinfos on the fluidity of some native membranes, namely erythrocytes, lymphocytes, brain microsomes, and sarcoplasmic reticulum, depended on the cholesterol content of these membranes.
7
Does membrane fluidity depend on Na - K -ATPase activity?
75%
Walkowiak B. , Koziolkiewicz W. , Borkowska E. , Cierniewski C. S.
Biophysics of Membrane Transport
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1994
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tom 12
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nr 2
8
Gemini ester quat surfactants and their biological activity
63%
Luczynski J. , Frackowiak R. , Wloch A. , Kleszczynska H. , Witek S.
Cellular and Molecular Biology Letters
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2013
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tom 18
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nr 1
EN
Cationic gemini surfactants are an important class of surface-active compounds that exhibit much higher surface activity than their monomeric counterparts. This type of compound architecture lends itself to the compound being easily adsorbed at interfaces and interacting with the cellular membranes of microorganisms. Conventional cationic surfactants have high chemical stability but poor chemical and biological degradability. One of the main approaches to the design of readily biodegradable and environmentally friendly surfactants involves inserting a bond with limited stability into the surfactant molecule to give a cleavable surfactant. The best-known example of such a compound is the family of ester quats, which are cationic surfactants with a labile ester bond inserted into the molecule. As part of this study, a series of gemini ester quat surfactants were synthesized and assayed for their biological activity. Their hemolytic activity and changes in the fluidity and packing order of the lipid polar heads were used as the measures of their biological activity. A clear correlation between the hemolytic activity of the tested compounds and their alkyl chain length was established. It was found that the compounds with a long hydrocarbon chain showed higher activity. Moreover, the compounds with greater spacing between their alkyl chains were more active. This proves that they incorporate more easily into the lipid bilayer of the erythrocyte membrane and affect its properties to a greater extent. A better understanding of the process of cell lysis by surfactants and of their biological activity may assist in developing surfactants with enhanced selectivity and in widening their range of application.
9
The interactions of PVP complexes of gossypol and its derivatives with an artificial membrane lipid matrix
63%
Ionov M. , Tukfatullina I. , Salakhutdinov B. , Baram N. , Bryszewska M. , Aripov T.
Cellular and Molecular Biology Letters
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2010
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tom 15
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nr 1
98-117
EN
In this paper, we present the results of a study on the membrane-active properties of gossypol, its derivatives and their polyvinylpyrrolidone complexes as assessed by differential scanning calorimetry and by the fluorescent probe method. The latter revealed the change in polarization of the incident radiation caused by the action of the polyphenol on the artificial membrane lipid matrix.
10
Content available remote Fenofibrate subcellular distribution as a rationale for the intracranial delivery through biodegradable carrier
63%
Grabacka M. , Waligorski P. , Zapata A. , Blake D. A. , Wyczechowska D. , Wilk A. , Rutkowska M. , Vashistha H. , Ayyala R. , Ponnusamy T. , John V. T. , Culicchia F. , Wisniewska-Becker A. , Reiss K.
Journal of Physiology and Pharmacology
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2015
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tom 66
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nr 2
11
Paraquat-induced changes in the structure of erythrocyte membranes are not caused by lipid peroxidation
63%
Gwozdzinski K.
|
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tom 18
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nr 2
12
Carbamylation of proteins leads to alterations in the membrane structure of erythrocytes
63%
Pieniazek A. , Gwozdzinski K.
Cellular and Molecular Biology Letters
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2003
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tom 08
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nr 1
EN
The effect of the sodium cyanate-induced carbamylation (carbamoylation) of proteins in erythrocytes was studied using spin labelling and spectrophotometric methods. The experiments were conducted in whole blood and in erythrocytes in phosphate buffer using 25 mmol/L of sodium cyanate. Lipid membrane fluidity was determined using three spin-labelled fatty acids: 5-, 12- and 16-doxylstearic acids (5-DS, 12-DS, 16-DS). Internal viscosity was measured with Tempamine, using also EPR spectroscopy. Osmotic fragility was determined spectrophotometrically. Incubation of whole blood with sodium cyanate led to an increase in lipid membrane fluidity in the deeper region of the lipid layer, indicated by 12- and 16-doxylstearic acid, and a decrease near the surface (5-DS). Statistically significant results were obtained for the internal viscosity and osmotic fragility of erythrocytes. An increase in internal viscosity and increase in osmotic fragility were found in erythrocytes after incubation of whole blood, as well as in erythrocytes incubated with sodium cyanate in buffer. Alterations in internal viscosity were stronger in erythrocytes incubated with sodium cyanate in blood than in erythrocytes in the buffer. On the other hand, higher osmotic fragility was observed for erythrocytes in the buffer.
13
Assessment of biological activity of new compounds designated to act as lysosomotropes
63%
Kleszczynska H. , Bonarska D. , Luczynski J. , Witek S. , Sarapuk J.
Polish Journal of Environmental Studies
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2005
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tom 14
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nr 6
EN
This work contains the results of studies on the influence of new lysosomotropic substances on an erythrocyte membrane. The compounds studied were hydrochlorides of N,N-dimethylglycine alkyl esters (DMG-n) and N,N-dimethylalanine alkyl esters (DMAL-n) having two different-length alkyl chains (n = 12 and 16), oxalates of dimethylaminoalaninates (DMALs -n; n = 8, 10, 12, 14 and 16) and methobromides of glycinates and alaninates (DMALM-12 and DMGM-12). They were found to hemolyze erythrocytes, to change their osmotic resistance and to influence erythrocyte membrane fluidity. The results obtained indicate that observed changes were dependent on lipophilicities of the compounds. It was especially evident in the case of hemolytic efficiencies of the homologous series of alanine oxalates. Also, DMG-n and DMAL-n compounds significantly differed in their hemolytic properties. Again, slightly better hemolytic efficiency of DMG compounds in comparison with corresponding compounds having the same alkyl chain, DMAL, confirm such a conclusion. However, their hemolytic efficiencies were found to be moderate, which makes them potentially useful membrane modifiers. That feature is important for lysosomotropic compounds and its confirmation was the primary aim of the presented work. It is worth mentioning that DMGM and DMALM compounds exhibited better hemolytic efficiencies than all other compounds studied – which is probably caused by the fact that they were used as bromides. Bromides are commonly found to be more active than compounds with other counterions.
14
Content available remote Fluidising effect of resorcylidene aminoguanidine on sarcolemmal membranes in streptozotocin-diabetic rats: blunted adaptation of diabetic myocardium to Ca2plus overload
63%
Waczulikova I. , Ziegelhoffer A. , Orszaghova Z. , Carsky J.
Journal of Physiology and Pharmacology
|
2002
|
tom 53
|
nr 4,2
EN
The "remodelling" of cardiac sarcolemma in diabetes is believed to underlie the reduced sensitivity of diabetic hearts due to their overload with extracellular calcium. Along with a non-enzymatic glycosylation and the free radical-derived glycoxidation of sarcolemmal proteins there is ongoing reduction in cardiomyocyte membrane fluidity, the modulator of cardiac sarcolemmal functioning. Aminoguanidine derivatives, that inhibit glycation and glycoxidation, might suppress myocardium "remodelling" occurring in diabetic heart. To verify this hypothesis, we studied physical parameters of cardiac sarcolemma from the streptozotocin-induced diabetic rats (45 mg.kg-1 i.m.) treated with resorcylidene aminoguanidine (RAG, 4 or 8 mg.kg-1 i.m.). The treatment with RAG not only completely abolished protein glycation and a generation of free oxygen species (p<0.001) in treated diabetic animals, but also considerably attenuated the decrease in sarcolemmal membrane fluidity (p<0.001). In diabetic animals the "normalizatio". of the sarcolemmal membrane fluidity was accompanied by the vastly increased susceptibility of diabetic hearts to be overload with external calcium. We concluded that the decreased fluidity of the sarcolemmal membrane, apparently linked to the excessive glycation of sarcolemmal membrane proteins, might be intimately connected with the adaptation mechanism(s) that are likely to develop in diabetic heart to protect it against the overload with external calcium.
15
Effect of nonionizing fields on biological membranes
63%
Ali F. M. , Ghanam M. , Elrefaei G. F. , Elgebaly R. , Abou-El-Ela K. , Hussein A. , Surour D. , Mohamed I.
Biophysics of Membrane Transport. Supplement
|
1994
|
tom 12
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