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This paper is a review of studies on the interaction between cationic, amphiphilic quaternary ammonium salts and biological and model membranes. It has been pointed out that the compounds studied induce changes in both passive and active membrane properties such as mechanical, transport liquid-crystalline and electrical . An attempt has been made to explain the observed effects on the basis of the molecular shape and hydrophobic matching concepts. Some practical implications of the observations and their interpretation have also been noted.
This paper studies the influence of equimolar mixtures of biologically-active cationic and anionic amphiphiles (dodecyl-oxymethylene-methyl-morpholinium chloride (DOMM) and one of the series of sodium alkylsulphonates (ASJ with n = 1,2,4,6,8,10,12 and 14 carbon atoms in the alkyl chain) on calcium ion desorption from lecithin liposome membranes. It was shown that by choosing the hydrophobic part of the amphiphilic anion in the mixture one can regulate the efficiency of the amphiphilic cation towards the desorption process. The rate constant of that process strongly depends on the surfactant concentration. The differences in the effectiveness of the different compounds are most distinct at lower concentrations and vanish when the concentration increases. The results are discussed in response to the amphiphilic ion-pair hydrophobicity and their electrical properties. The role of the hypothetical, temporal complexes consisting of the alkylsulphonate anion(s) and calcium cation (ASn-Ca)+ in the calcium ion exchange is discussed. The mechanism of Ca2+ desorption from the surface of the phospholipid bilayer under the simultaneous action of the cationic and anionic detergents is proposed. According to our proposal calcium ion release occurs due to the joint action of the monovalent cationic and anionic detergents in coincidence with a divalent calcium ion. To authenticate the proposed mechanisms of calcium ion release, the shapes of the experimental curves were compared with the theoretical ones obtained by computer simulation using the cellular automata method.
The cellular automaton method was used to simulate the process of ion desorption from the surface of lipid membranes modified with a mixture of cationic and anionic amphiphile molecules. Three models were devised to analyze the influence of anionic long-chain and cationic long-chain compounds, and a mixture of anionic short chain and cationic long chain compounds on bipositive ion desorption. The obtained results are compared with experimental results. These models show the significance of some hypotheses on the role of temporal complexes of the alkylsulphonate anion and calcium ion, of readsorption of calcium ions, and of different methods of molecular aggregation on the kinetics of calcium desorption.
Studies were carried out on the effect of chloride of N-dodecyl-betaine 2-chloroethyl-ester (BE V-B), and chloride of betaine 2-chloroethyl-ester (BE V-B), added to liposomes formed of egg yolk lecithin, on the order parameter of a spin probe incorporated in the temperature range 2-50 °C. The BE’s used here modified ESR spectra to various degrees and lowered the order parameter of the spin probe. At temperatures lower than 20 °C compound V-B caused smaller changes in the order parameter than V-A, whereas above that temperature it caused greater changes. The ESR spectra of liposomes containing BE's exhibited splitting into two components that corresponded to different order parameter values. The molecular mechanism of interaction between the compounds studied and liposomes is disscused.
On the basis of Gortel & Grendel (J. Exp. Med., 1925, 41, 439-494) discovery, the importance of the lipid bilayer as an integral and indispensible component of the cell membrane is discussed. In particular, attention focuses on the interaction between membranes and amphiphilic substances. The effect on membranes of quaternary ammonium salts, both in the form of pesticides and oxidants as well as organic compounds of tin and lead are discussed in greater detail.
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