Interaction Mechanism of Cortisol and Catecholamines with Structural Components of Erythrocyte Membranes

2010 ◽  
Vol 114 (29) ◽  
pp. 9462-9473 ◽  
Author(s):  
Lev Evgenjevich Panin ◽  
Pavel Valentinovich Mokrushnikov ◽  
Valery Georgievich Kunitsyn ◽  
Boris Nikolaevich Zaitsev
Keyword(s):  
Interaction Mechanism ◽  
Erythrocyte Membranes ◽  
Structural Components

Interaction Mechanism of Anabolic Steroid Hormones with Structural Components of Erythrocyte Membranes

2011 ◽  
Vol 115 (50) ◽  
pp. 14969-14979 ◽  
Author(s):  
Lev Evgenjevich Panin ◽  
Pavel Valentinovich Mokrushnikov ◽  
Valery Georgievich Kunitsyn ◽  
Boris Nikolaevich Zaitsev
Keyword(s):  
Steroid Hormones ◽  
Anabolic Steroid ◽  
Interaction Mechanism ◽  
Erythrocyte Membranes ◽  
Structural Components

Perturbational actions of barbiturate analogues on erythrocyte and synaptosomal membranes

1985 ◽  
Vol 63 (8) ◽  
pp. 937-943 ◽  
Author(s):  
David V. Godin ◽  
Peter McGinn
Keyword(s):  
Membrane Proteins ◽  
Local Anaesthetics ◽  
Erythrocyte Membranes ◽  
Synaptosomal Membranes ◽  
Structural Components ◽  
Chemical Probes ◽  
Trinitrobenzenesulfonic Acid ◽  
Specific Chemical ◽  
Nitrobenzoic Acid ◽  
Acid Incorporation

The membrane perturbational actions of pentobarbital, methohexital, and phenobarbital were analyzed in terms of their effects on the incorporation of group-specific chemical probes into protein and phospholipid structural components and on the activity of various functionally distinct ATPases in erythrocyte and brain synaptosomal membranes. When compared at concentrations producing similar degrees of antihemolysis in red cells, the three analogues differed most markedly in the nature and degree of the structural and functional alterations induced in membrane proteins, with the most highly lipophilic agent, methohexital, being frequently, although not invariably, the most potent. Comparison of the effects of pentobarbital on characteristics of trinitrobenzenesulfonic acid and 5,5′-dithiobis-(2-nitrobenzoic acid) incorporation into erythrocyte membranes with results previously obtained using other anaesthetics at concentrations producing 50% antihemolysis showed that pentobarbital behaves similarly to neutral general anaesthetics but differently from cationic local anaesthetics. Our findings suggest that the membrane perturbational characteristics of barbiturates may contribute to their diverse and complex actions on excitable tissues.

Antioxidative Activity of New N-Oxides of Tertiary Amines: Membrane Model and Chromogen Studies

2005 ◽  
Vol 60 (7-8) ◽  
pp. 567-571 ◽  
Author(s):  
Halina Kleszczyńska ◽  
Dorota Bonarska ◽  
Hanna Pruchnik ◽  
Krzysztof Bielecki ◽  
Andrzej Piasecki ◽  
...  
Keyword(s):  
Alkyl Chain ◽  
Radical Scavenging ◽  
Interaction Mechanism ◽  
Membrane Lipid ◽  
Water Soluble ◽  
Erythrocyte Membranes ◽  
Scanning Calorimetry ◽  
Dsc Measurements ◽  
Main Transition ◽  
Liposomal Membranes

Potential antioxidative activities of three series of newly synthesized N-oxides were studied. Individual components in each of the series differed in the lipophilicities and number of free radical scavenging groups. Various methods were used to determine their antioxidative efficiencies: Prevention of erythrocyte membrane lipid oxidation induced by UV irradiation and chromogen experiments in which antioxidative efficiencies of compounds were compared to that of the standard antioxidant Trolox (a water-soluble vitamin E analogue). Additionally, some hemolytic (pig erythrocytes) and differential scanning calorimetry (DSC) measurements were performed to determine a mechanism of the interaction between membranes and N-oxides. It was found that N-oxides, especially those of long alkyl chains (> C12H25), readily interacted with both, erythrocyte and liposomal membranes. No marked differences were found in their protection of erythrocytes against oxidation. In most cases inhibition of oxidation changed between 15% and 25%. Still, it was far better than in chromogen experiments where suppression of free radicals reached 20% in the best case. It may be concluded that antioxidative capabilities of N-oxides are moderate. Studies on the interaction mechanism showed that incorporation of particular compounds into model membranes varied. Hemolysing activities of compounds increased with the elongation of the alkyl chain but differed for corresponding compounds of particular series indicating that lipophilicity of compounds is not the only factor determing their interaction with erythrocyte membranes. DSC experiments showed that N-oxides, upon incorporation into 1,2-dipalmitoyl-3-snphosphatidylcholine liposomes, shifted the subtransition (Tp) and the main transition (Tm). The shifts observed depended on the alkyl chain length. The effects differed for each series. It seems that in the case of long alkyl chain compounds the domain formation may take place. Generally, the decrease of Tm was greatest for the same compounds that exhibited the best hemolytic efficacy. The same conclusion concerns the decrease of cooperativity of the main transition and the observed changes suggest an increase in membrane fluidity. Both, erythrocyte and DSC experiments seem to indicate that compounds of particular series incorporate in a somewhat different way into membranes.

Electron probe x-ray microanalysis and electron microscopy of amino acid absorption and transport by the small intestine: inhibition by chemical poisons and correlation to the elemental composition of the epithelial cells

1986 ◽  
Vol 44 ◽  
pp. 134-135
Author(s):  
A. J. Tousimis
Keyword(s):  
Small Intestine ◽  
Amino Acid ◽  
Epithelial Cells ◽  
Elemental Composition ◽  
Isotope Labeling ◽  
Structural Components ◽  
X Ray ◽  
Human Small Intestine ◽  
Transport Studies

The elemental composition of amino acids is similar to that of the major structural components of the epithelial cells of the small intestine and other tissues. Therefore, their subcellular localization and concentration measurements are not possible by x-ray microanalysis. Radioactive isotope labeling: I131-tyrosine, Se75-methionine and S35-methionine have been successfully employed in numerous absorption and transport studies. The latter two have been utilized both in vitro and vivo, with similar results in the hamster and human small intestine. Non-radioactive Selenomethionine, since its absorption/transport behavior is assumed to be the same as that of Se75- methionine and S75-methionine could serve as a compound tracer for this amino acid.

Freeze-fracture cytochemistry: A goal set by Russell Steere in 1957

1993 ◽  
Vol 51 ◽  
pp. 60-61
Author(s):  
Nicholas J Severs
Keyword(s):  
Chemical Nature ◽  
Biological Systems ◽  
Freeze Fracture ◽  
Structural Components ◽  
Major Goal ◽  
Membrane Biology ◽  
Routine Application ◽  
The Future ◽  
Freeze Etching

In his pioneering demonstration of the potential of freeze-etching in biological systems, Russell Steere assessed the future promise and limitations of the technique with remarkable foresight. Item 2 in his list of inherent difficulties as they then stood stated “The chemical nature of the objects seen in the replica cannot be determined”. This defined a major goal for practitioners of freeze-fracture which, for more than a decade, seemed unattainable. It was not until the introduction of the label-fracture-etch technique in the early 1970s that the mould was broken, and not until the following decade that the full scope of modern freeze-fracture cytochemistry took shape. The culmination of these developments in the 1990s now equips the researcher with a set of effective techniques for routine application in cell and membrane biology.Freeze-fracture cytochemical techniques are all designed to provide information on the chemical nature of structural components revealed by freeze-fracture, but differ in how this is achieved, in precisely what type of information is obtained, and in which types of specimen can be studied.

Microtubule motors and other maps

1990 ◽  
Vol 48 (3) ◽  
pp. 1-1
Author(s):  
Richard B. Vallee
Keyword(s):  
Molecular Weight ◽  
High Molecular Weight ◽  
Cytoplasmic Dynein ◽  
Organelle Transport ◽  
Structural Components ◽  
Microtubule Associated Proteins ◽  
Microtubule Motors ◽  
Associated Proteins ◽  
The Subject ◽  
Intracellular Motility

Microtubules are involved in a number of forms of intracellular motility, including mitosis and bidirectional organelle transport. Purified microtubules from brain and other sources contain tubulin and a diversity of microtubule associated proteins (MAPs). Some of the high molecular weight MAPs - MAP 1A, 1B, 2A, and 2B - are long, fibrous molecules that serve as structural components of the cytamatrix. Three MAPs have recently been identified that show microtubule activated ATPase activity and produce force in association with microtubules. These proteins - kinesin, cytoplasmic dynein, and dynamin - are referred to as cytoplasmic motors. The latter two will be the subject of this talk.Cytoplasmic dynein was first identified as one of the high molecular weight brain MAPs, MAP 1C. It was determined to be structurally equivalent to ciliary and flagellar dynein, and to produce force toward the minus ends of microtubules, opposite to kinesin.

Three-Dimensional Reconstruction of Two Forms of the Chaperonin GRO EL

1990 ◽  
Vol 48 (1) ◽  
pp. 258-259
Author(s):  
J.L. Carrascosa ◽  
G. Abella ◽  
S. Marco ◽  
M. Muyal ◽  
J.M. Carazo
Keyword(s):  
Three Dimensional ◽  
The Other ◽  
Two Dimensional ◽  
Series Method ◽  
Three Dimensional Reconstruction ◽  
Structural Components ◽  
E Coli ◽  
Dimensional Reconstruction ◽  
Morphogenetic Factors ◽  
Tilt Series

Chaperonins are a class of proteins characterized by their role as morphogenetic factors. They trantsiently interact with the structural components of certain biological aggregates (viruses, enzymes etc), promoting their correct folding, assembly and, eventually transport. The groEL factor from E. coli is a conspicuous member of the chaperonins, as it promotes the assembly and morphogenesis of bacterial oligomers and/viral structures.We have studied groEL-like factors from two different bacteria:E. coli and B.subtilis. These factors share common morphological features , showing two different views: one is 6-fold, while the other shows 7 morphological units. There is also a correlation between the presence of a dominant 6-fold view and the fact of both bacteria been grown at low temperature (32°C), while the 7-fold is the main view at higher temperatures (42°C). As the two-dimensional projections of groEL were difficult to interprete, we studied their three-dimensional reconstruction by the random conical tilt series method from negatively stained particles.

Effect of Integral Proteins on Frozen Membrane Fracture

1980 ◽  
Vol 38 ◽  
pp. 756-759 ◽  
Author(s):  
S. Kirchanski ◽  
D. Branton
Keyword(s):  
Lipid Bilayers ◽  
Freeze Fracture ◽  
Covalent Bond ◽  
Erythrocyte Membranes ◽  
Glycophorin A ◽  
Experimental Protocol ◽  
Transmembrane Glycoprotein ◽  
Bond Breakage ◽  
Human Erythrocyte Membranes ◽  
Integral Proteins

We have investigated the effect of integral membrane proteins upon the fracturing of frozen lipid bilayers. This investigation has been part of an effort to develop freeze fracture labeling techniques and to assess the possible breakage of covalent protein bonds during the freeze fracture process. We have developed an experimental protocol utilizing lectin affinity columns which should detect small amounts of covalent bond breakage during the fracture of liposomes containing purified (1) glycophorin (a transmembrane glycoprotein of human erythrocyte membranes). To fracture liposomes in bulk, frozen liposomes are ground repeatedly under liquid nitrogen. Failure to detect any significant covalent bond breakage (contrary to (2)) led us to question the effectiveness of our grinding procedure in fracturing and splitting lipid bilayers.

Variations in the Lipid Profile of Patients with Chronic Renal Failure, Treated with Folic Acid

2003 ◽  
Vol 73 (3) ◽  
pp. 215-220 ◽  
Author(s):  
de Gómez Dumm ◽  
Giammona ◽  
Touceda
Keyword(s):  
Renal Failure ◽  
Folic Acid ◽  
Chronic Renal Failure ◽  
Density Lipoprotein ◽  
Plasma Homocysteine ◽  
Lipid Profiles ◽  
Erythrocyte Membranes ◽  
Favorable Effect ◽  
High Dose ◽  
Acid Therapy

Dyslipidemia and increases in plasma homocysteine usually occur at end-stage renal disease; both are recognized as risk factors for atherosclerosis. Folate administration reduces homocysteine concentration. In this study we determined the effect of a high dose of folic acid (40 mg intravenous injection three times a week) on plasma and red blood cell lipid profiles in twelve chronic renal failure patients on regular hemodialysis. Fasting blood samples were taken at the beginning of the study (baseline) and after 21, 42, and 64 days of treatment. Folic acid supplementation decreased plasma homocysteine. Plasma triglyceride levels decreased whereas polyunsaturated fatty acid values increased after 21 days; then they returned to baseline levels at the end of treatment. Total cholesterol and low-density lipoprotein (LDL) cholesterol were higher than those of the baseline during all the study, whereas high-density lipoprotein (HDL) cholesterol was reduced. In erythrocyte membranes, folic acid therapy enhanced cholesterol/phospholipid ratios and the fluorescence anisotropy of diphenyl-hexatriene. We conclude that large doses of folic acid produce a favorable effect, reducing plasma homocysteine levels and protecting patients from atherosclerosis. However, as this therapy induces significant alterations in both plasma and erythrocyte membrane lipid profiles, plasma lipid values should be controlled throughout the treatment of patients with renal failure.

The formation of information security culture of college students

2019 ◽  
pp. 29-36
Author(s):  
I. D. Rudinskiy ◽  
D. Ya. Okolot
Keyword(s):  
College Students ◽  
Information Security ◽  
Information Society ◽  
Technical Aspect ◽  
Data Sources ◽  
Structural Components ◽  
Security Culture ◽  
The Individual ◽  
Information Security Culture ◽  
Ability And Willingness

The article discusses aspects of the formation of information security culture of college students. The relevance of the work is due to the increasing threats to the information security of the individual and society due to the rapid increase in the number of information services used. Based on this, one of the important problems of the development of the information society is the formation of a culture of information security of the individual as part of the general culture in its socio-technical aspect and as part of the professional culture of the individual. The study revealed the structural components of the phenomenon of information security culture, identified the reasons for the interest in the target group of students. It justifies the need for future mid-level specialists to form an additional universal competency that ensures the individual’s ability and willingness to recognize the need for certain information, to identify and evaluate the reliability and reliability of data sources. As a result of the study, recommendations were formulated on the basis of which a culture of information security for college students can be formed and developed and a decomposition of this process into enlarged stages is proposed. The proposals on the list of disciplines are formulated, within the framework of the study of which a culture of information security can develop. The authors believe that the recommendations developed will help future mid-level specialists to master the universal competency, consisting in the ability and willingness to recognize the need for certain information, to identify and evaluate the reliability and reliability of data sources, as well as to correctly access the necessary information and its further legitimate use, which ultimately forms a culture of information security.

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