Influence of phosphatidylserine on (Na+ + K+)-stimulated ATPase and acetylcholinesterase activities of dog brain synaptosomal plasma membranes

Phosphatidylserine (PtdSer) incubated with synaptosomal plasma membranes (SPM) of dog brain is incorporated into SPM in proportion to its concentration in the incubation medium. Low PtdSer concentrations progressively activated the SPM-associated (Na+ + K+)-stimulated ATPase and acetylcholinesterase. Increasing the PtdSer concentration above that which maximally stimulated the enzyme activities effected a progressive inhibition with respect to maximal stimulation. Arrhenius plots of (Na+ + K+ + Mg2+)-dependent ATPase and 5′-nucleotidase revealed a clear break at 23-24 degrees C for both enzymes in SPM untreated with PtdSer (controls), whereas a linear relation was obtained for SPM treated with PtdSer. Changes in the allosteric properties of (Na+ + K+)-stimulated ATPase by fluoride (F-) and/or of 5′-nucleotidase by concanavalin A (i.e. changes of Hill coefficients) indicate that PtdSer increases the membrane fluidity. These results suggest that modifications of lipid-protein interactions in SPM induced by PtdSer may have implications in the physiological processes in the central nervous system.

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Stimulation of Brain Synaptosome - Associated Adenylate Cyclase by Acidic Phospholipids

Zeitschrift für Naturforschung C ◽

10.1515/znc-1984-11-1237 ◽

1984 ◽

Vol 39 (11-12) ◽

pp. 1196-1198 ◽

Cited By ~ 1

Author(s):

Stylianos Tsakiris

Keyword(s):

Enzyme Activity ◽

Adenylate Cyclase ◽

Plasma Membranes ◽

Protein S ◽

Enzyme Activation ◽

Dog Brain ◽

The Central Nervous System ◽

Acidic Phospholipids ◽

Synaptosomal Plasma Membranes ◽

Stimulation Of

Phosphatidylserine (PS), phosphatidylinositol (PIN) or phosphatidylglycerol (PGL) incubated with synaptosomal plasma membranes (SPM) of dog brain, stimulated adenylate cyclase. The enzyme activity showed a dramatic increase at around 1.6 μmol PS/mg protein, while use of higher concentrations led to inhibition of the activity with respect to the maximal percentage of stimulation. Moreover, PS stimulated the dopamine-sensitive adenylate cyclase. Solubilization of SPM by the detergent Lubrol-PX did not affect the enzyme activation induced by dopamine. The solubilization, also, showed that the enzyme activity does not change at any PS, PIN or PGL concentration used. These results indicate that acidic phospholipids do not directly act on adenylate cyclase, but indirectly, affecting the membrane fluidity probably. Such modifications of interactions through lipid-protein(s) of adenylate cyclase may have implications to physiological responses to hormones or/and neurotransm itters in the central nervous system.

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Evoked effects of cholesterol binding on integral proteins and lipid fluidity of dog brain synaptosomal plasma membranes

Biochemistry and Cell Biology ◽

10.1139/o89-003 ◽

1989 ◽

Vol 67 (1) ◽

pp. 16-24 ◽

Cited By ~ 11

Author(s):

George Deliconstantinos ◽

Lioudmila Kopeikina ◽

Vassiliki Villiotou

Keyword(s):

Fluorescence Polarization ◽

Plasma Membranes ◽

Specific Activity ◽

Break Point ◽

Hill Coefficient ◽

Dog Brain ◽

Integral Proteins ◽

The Hill ◽

Synaptosomal Plasma Membranes ◽

Allosteric Properties

Binding of cholesterol into dog brain synaptosomal plasma membranes (SPM) within the limits of concentration used (0.5–5 μM) follows an exponential curve described by the general formula y = a∙ebx. This curve, which represents the total binding (specific and nonspecific), acquires sigmoid character in the presence of 100 μM cholesterol glucoside, with a Hill coefficient of h = 2.98 ± 0.18. The specific activity of the Na+/K+-transporting ATPase and Ca2+-transporting ATPase rose after a 2-h preincubation of SPM with cholesterol (up to 5 μM) or its glucoside (up to 50 μM) to at least 50% above their original values. Fluorescence polarization of 1,6-diphenyl-1,3,5-hexatriene (DPH) increased with cholesterol glucoside (50 μM) incorporation. Cholesterol (5 μM) had no effect on the DPH fluorescence polarization. Arrhenius plots of Na+/K+-transporting ATPase activity exhibited a break point at 23.2 ± 1.1 °C in control SPM, which was elevated to 29.5 ± 1.4 °C in SPM treated with cholesterol glucoside (50 μM) and abolished in SPM treated with cholesterol (5 μM). The allosteric properties of SPM-bound Na+/K+-transporting ATPase inhibited by F− and Ca2+-transporting ATPase inhibited by Na+ (as reflected by changes in the Hill coefficient) were modulated by cholesterol. It could be stated that cholesterol glucoside (50 μM) produced an increased packing of the bulk lipids, while cholesterol (5 μM) increased the fluidity of the lipid microenvironment of both Na+/K+-transporting ATPase and Ca2+-transporting ATPase.Key words: cholesterol, cholesterol glucoside, (NA+/K+)ATPase, Ca2+-ATPase, membrane fluidity, fluorescence polarization.

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Control of the Activity of Brain Synaptosome-Associated Acetylcholinesterase by Acidic Phospholipids

Zeitschrift für Naturforschung C ◽

10.1515/znc-1985-1-219 ◽

1985 ◽

Vol 40 (1-2) ◽

pp. 97-101 ◽

Cited By ~ 6

Author(s):

Stylianos Tsakiris

Keyword(s):

Ache Activity ◽

Plasma Membranes ◽

Protein Molecule ◽

Break Point ◽

Arrhenius Activation Energy ◽

Physiological Processes ◽

The Central Nervous System ◽

Acidic Phospholipids ◽

Enzyme Stimulation ◽

Synaptosomal Plasma Membranes

Abstract Incubation of synaptosomal plasma membranes (SPM) with liposomes of phosphatidylserine (PS), phosphatidylinositol (PIN) or phosphatidylglycerol (PGL), led to an increase of acetylcholinesterase (AchE) activity at concentrations of 0.1-1 μmol phospholip ids per mg SPM protein. The use of higher concentrations (1-7 μmol/mg protein), however, led to a progressive inhibition of the activity with respect to the maximal percentage of enzyme stimulation. To explain the enzyme stimulation by the acidic phospholipids, AchE was solubilized with the detergent Lubrol-PX and showed no change in the enzyme activity at any PS, PIN or PGL concentration used, indicating that these compounds do not act on the protein molecule directly. Arrhenius plots of AchE activities in untreated SPM (control), exhibited a break point at 23 °C , which was decreased to 16-17 °C in PS-treated SPM. Moreover, the Arrhenius activation energy (Ea) value in PS-treated SPM was increased related to the Ea below the break point in the control. These results indicate that acidic phospholipids do not act on AchE directly, but indirectly, affecting the membrane fluidity probably. Such modifications of interactions between lipid and AchE may control physiological processes in the central nervous system .

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Haemolytic actinoporins interact with carbohydrates using their lipid-binding module

Philosophical Transactions of the Royal Society B Biological Sciences ◽

10.1098/rstb.2016.0216 ◽

2017 ◽

Vol 372 (1726) ◽

pp. 20160216 ◽

Cited By ~ 5

Author(s):

Koji Tanaka ◽

Jose M. M. Caaveiro ◽

Koldo Morante ◽

Kouhei Tsumoto

Keyword(s):

Protein Interactions ◽

Pore Formation ◽

Plasma Membranes ◽

Lipid Binding ◽

Target Cells ◽

Sea Anemones ◽

Molecular Systems ◽

Membrane Pores ◽

Living Organisms ◽

Lipid Protein Interactions

Pore-forming toxins (PFTs) are proteins endowed with metamorphic properties that enable them to stably fold in water solutions as well as in cellular membranes. PFTs produce lytic pores on the plasma membranes of target cells conducive to lesions, playing key roles in the defensive and offensive molecular systems of living organisms. Actinoporins are a family of potent haemolytic toxins produced by sea anemones vigorously studied as a paradigm of α-helical PFTs, in the context of lipid–protein interactions, and in connection with nanopore technologies. We have recently reported that fragaceatoxin C (FraC), an actinoporin, engages biological membranes with a large adhesive motif allowing the simultaneous attachment of up to four lipid molecules prior to pore formation. Since actinoporins also interact with carbohydrates, we sought to understand the molecular and energetic basis of glycan recognition by FraC. By employing structural and biophysical methodologies, we show that FraC engages glycans with low affinity using its lipid-binding module. Contrary to other PFTs requiring separate domains for glycan and lipid recognition, the small single-domain actinoporins economize resources by achieving dual recognition with a single binding module. This mechanism could enhance the recruitment of actinoporins to the surface of target tissues in their marine environment. This article is part of the themed issue ‘Membrane pores: from structure and assembly, to medicine and technology’.

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Lipid-mediated Association of the Slg1 Transmembrane Domains in Yeast Plasma Membranes

10.1101/2021.06.29.450341 ◽

2021 ◽

Author(s):

Azadeh Alavizargar ◽

Annegret Eltig ◽

Roland Wedlich Soeldner ◽

Andreas Heuer

Keyword(s):

Plasma Membrane ◽

Protein Interactions ◽

Plasma Membranes ◽

Acyl Chain ◽

Md Simulations ◽

Receptor Activation ◽

Transmembrane Domains ◽

Coarse Grained ◽

Self Association ◽

Lipid Protein Interactions

Clustering of transmembrane proteins underlies a multitude of fundamental biological processes at the plasma membrane such as receptor activation, lateral domain formation and mechanotransduction. The self-association of the respective transmembrane domains (TMD) has also been suggested to be responsible for the micron-scaled patterns seen for integral membrane proteins in the budding yeast plasma membrane (PM). However, the underlying interplay between local lipid composition and TMD identity is still not mechanistically understood. In this work we have used coarse-grained molecular dynamics (MD) simulations as well as microscopy experiments (TIRFM) to analyze the behavior of a representative helical yeast TMD (Slg1) within different lipid environments. Via the simulations we evaluated the effect of acyl chain saturation and the presence of anionic lipids head groups on the association of TMDs via simulations. Our simulations revealed that weak lipid-protein interactions significantly affect the configuration of TMD dimers and the free energy of association. Increased amounts of unsaturated phospholipids strongly reduced helix-helix interaction and the presence of phosphatidylserine (PS) lipids only slightly affected the dimer. Experimentally, the network factor, characterizing the association strength on a mesoscopic level, was measured in the presence and absence of PS lipids. Consistently with the simulations, no significant effect was observed. We also found that formation of TMD dimers in turn increased the order parameter of the surrounding lipids and induced long-range perturbations in lipid organization, shedding new light on the lipid-mediated dimerization of TMDs in complex lipid mixtures.

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Differential effect of anionic and cationic drugs on the synaptosome-associated acetylcholinesterase activity of dog brain

Biochemical Journal ◽

10.1042/bj2290081 ◽

1985 ◽

Vol 229 (1) ◽

pp. 81-86 ◽

Cited By ~ 13

Author(s):

G Deliconstantinos ◽

S Tsakiris

Keyword(s):

Enzyme Activity ◽

Plasma Membranes ◽

Barbituric Acid ◽

Acetylcholinesterase Activity ◽

Break Point ◽

Low Concentrations ◽

Hill Coefficients ◽

The Hill ◽

Synaptosomal Plasma Membranes ◽

Positively Charged

The evoked effects of the negatively charged drugs phenobarbital and barbituric acid, the positively charged imipramine, perphenazine and trifluoperazine, and the neutral primidone, on the synaptosome-associated acetylcholinesterase activity were studied. A marked increase in the enzyme activity was exhibited in the presence of low concentrations (up to 3 mM) of phenobarbital, barbituric acid and primidone. Higher concentrations (up to 10 mM), however, led to a progressive inhibition of the enzyme activity. However, the activity of the enzyme was not affected by imipramine, but it was decreased by perphenazine and trifluoperazine. Arrhenius plots of acetylcholinesterase activity exhibited a break point at 23.4 degrees C for the untreated (control) synaptosomes, which was shifted to around 16 degrees C in the synaptosomes treated with the charged drugs. The allosteric inhibition by F- of acetylcholinesterase was studied in control synaptosomes and in those treated with the charged drugs. Changes in the Hill coefficients in combination with changes in Arrhenius activation energy produced by the charged drugs would be expected if it is assumed that charged drugs ‘fluidize’ the synaptosomal plasma membranes.

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