Journal articles: 'Membrane interaction'

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Csoboz, Balint, Imre Gombos, Zoltán Kóta, Barbara Dukic, Éva Klement, Vanda Varga-Zsíros, Zoltán Lipinszki, Tibor Páli, László Vígh, and Zsolt Török. "The Small Heat Shock Protein, HSPB1, Interacts with and Modulates the Physical Structure of Membranes." International Journal of Molecular Sciences 23, no. 13 (June 30, 2022): 7317. http://dx.doi.org/10.3390/ijms23137317.

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Small heat shock proteins (sHSPs) have been demonstrated to interact with lipids and modulate the physical state of membranes across species. Through these interactions, sHSPs contribute to the maintenance of membrane integrity. HSPB1 is a major sHSP in mammals, but its lipid interaction profile has so far been unexplored. In this study, we characterized the interaction between HSPB1 and phospholipids. HSPB1 not only associated with membranes via membrane-forming lipids, but also showed a strong affinity towards highly fluid membranes. It participated in the modulation of the physical properties of the interacting membranes by altering rotational and lateral lipid mobility. In addition, the in vivo expression of HSPB1 greatly affected the phase behavior of the plasma membrane under membrane fluidizing stress conditions. In light of our current findings, we propose a new function for HSPB1 as a membrane chaperone.

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Chang-Hwei, Chen, Stuart G. Engel, Carol Samsonoff, and Donald S. Berns. "Investigation of phycocyanin-membrane interaction: Promotion of membrane interactions." International Journal of Biochemistry 23, no. 3 (January 1991): 293–99. http://dx.doi.org/10.1016/0020-711x(91)90109-z.

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Smaal, Erik B., Jacqueline G. Mandersloot, Rudy A. Demel, Ben de Kruijff, and Johannes de Gier. "Consequences of the interaction of calcium with dioleoylphosphatidate-containing model membranes: calcium-membrane and membrane-membrane interactions." Biochimica et Biophysica Acta (BBA) - Biomembranes 897, no. 1 (February 1987): 180–90. http://dx.doi.org/10.1016/0005-2736(87)90326-9.

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Wang, Lu, Nicolas Hartel, Kaixuan Ren, Nicholas Alexander Graham, and Noah Malmstadt. "Effect of protein corona on nanoparticle–plasma membrane and nanoparticle–biomimetic membrane interactions." Environmental Science: Nano 7, no. 3 (2020): 963–74. http://dx.doi.org/10.1039/d0en00035c.

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A systematic study of the protein corona's effect on nanoparticle–biomembrane electrostatic interactions. Nanoparticle adhesion and membrane integrity upon interaction were compared between plasma membranes and biomimetic membranes.

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Sikorski, A. F., B. Hanus-Lorenz, A. Jezierski, and A. R. Dluzewski. "Interaction of membrane skeletal proteins with membrane lipid domain." Acta Biochimica Polonica 47, no. 3 (September 30, 2000): 565–78. http://dx.doi.org/10.18388/abp.2000_3979.

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The object of this paper is to review briefly the studies on the interaction of red blood cell membrane skeletal proteins and their non-erythroid analogues with lipids in model systems as well as in natural membranes. An important question to be addressed is the physiological significance and possible regulatory molecular mechanisms in which these interactions are engaged.

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Nastou, Katerina C., Georgios N. Tsaousis, Kimon E. Kremizas, Zoi I. Litou, and Stavros J. Hamodrakas. "The Human Plasma Membrane Peripherome: Visualization and Analysis of Interactions." BioMed Research International 2014 (2014): 1–12. http://dx.doi.org/10.1155/2014/397145.

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A major part of membrane function is conducted by proteins, both integral and peripheral. Peripheral membrane proteins temporarily adhere to biological membranes, either to the lipid bilayer or to integral membrane proteins with noncovalent interactions. The aim of this study was to construct and analyze the interactions of the human plasma membrane peripheral proteins (peripherome hereinafter). For this purpose, we collected a dataset of peripheral proteins of the human plasma membrane. We also collected a dataset of experimentally verified interactions for these proteins. The interaction network created from this dataset has been visualized using Cytoscape. We grouped the proteins based on their subcellular location and clustered them using the MCL algorithm in order to detect functional modules. Moreover, functional and graph theory based analyses have been performed to assess biological features of the network. Interaction data with drug molecules show that ~10% of peripheral membrane proteins are targets for approved drugs, suggesting their potential implications in disease. In conclusion, we reveal novel features and properties regarding the protein-protein interaction network created by peripheral proteins of the human plasma membrane.

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Milescu, Mirela, Jan Vobecky, Soung H. Roh, Sung H. Kim, Hoi J. Jung, Jae Il Kim, and Kenton J. Swartz. "Tarantula Toxins Interact with Voltage Sensors within Lipid Membranes." Journal of General Physiology 130, no. 5 (October 15, 2007): 497–511. http://dx.doi.org/10.1085/jgp.200709869.

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Voltage-activated ion channels are essential for electrical signaling, yet the mechanism of voltage sensing remains under intense investigation. The voltage-sensor paddle is a crucial structural motif in voltage-activated potassium (Kv) channels that has been proposed to move at the protein–lipid interface in response to changes in membrane voltage. Here we explore whether tarantula toxins like hanatoxin and SGTx1 inhibit Kv channels by interacting with paddle motifs within the membrane. We find that these toxins can partition into membranes under physiologically relevant conditions, but that the toxin–membrane interaction is not sufficient to inhibit Kv channels. From mutagenesis studies we identify regions of the toxin involved in binding to the paddle motif, and those important for interacting with membranes. Modification of membranes with sphingomyelinase D dramatically alters the stability of the toxin–channel complex, suggesting that tarantula toxins interact with paddle motifs within the membrane and that they are sensitive detectors of lipid–channel interactions.

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Matos, Anna Lívia Linard, Sergej Kudruk, Johanna Moratz, Milena Heflik, David Grill, Bart Jan Ravoo, and Volker Gerke. "Membrane Binding Promotes Annexin A2 Oligomerization." Cells 9, no. 5 (May 8, 2020): 1169. http://dx.doi.org/10.3390/cells9051169.

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Annexin A2 (AnxA2) is a cytosolic Ca2+ regulated membrane binding protein that can induce lipid domain formation and plays a role in exocytosis and endocytosis. To better understand the mode of annexin-membrane interaction, we analyzed membrane-bound AnxA2 assemblies by employing a novel 3-armed chemical crosslinker and specific AnxA2 mutant proteins. Our data show that AnxA2 forms crosslinkable oligomers upon binding to membranes containing negatively charged phospholipids. AnxA2 mutants with amino acid substitutions in residues predicted to be involved in lateral protein–protein interaction show compromised oligomer formation, albeit still being capable of binding to negatively charged membranes in the presence of Ca2+. These results suggest that lateral protein–protein interactions are involved in the formation of AnxA2 clusters on a biological membrane.

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Wang, Qinshi, Yun Zhang, Xianli Zhang, Qi Li, Mingcong Huang, Shasha Huang, Qianlian Wu, et al. "A Study of the Mechanism and Separation of Structurally Similar Phenolic Acids by Commercial Polymeric Ultrafiltration Membranes." Membranes 12, no. 3 (March 1, 2022): 285. http://dx.doi.org/10.3390/membranes12030285.

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This study examined the behavior and penetration mechanisms of typical phenolic (benzoic) acids, which determine their observed penetration rates during membrane separation, focusing on the influence of electrostatic and hydrophobic solute/membrane interactions. To understand the effects of hydrophobicity and electrostatic interaction on membrane filtration, the observed penetration of five structurally similar phenolic acids was compared with regenerated cellulose (RC) and polyamide (PA) membranes at different solute concentrations and solution pHs. Variation partitioning analysis (VPA) was performed to calculate the relative contributions of electrostatic and hydrophobic effects. The penetration of phenolic acids was mainly influenced by the electrostatic interaction, with salicylic acid having the highest penetration. Penetration of phenolic acids through the PA membrane decreased from 98% at pH 3.0 to 30–50% at pH 7.4, indicating the dominance of the electrostatic interaction. Moreover, based on its hydrophobicity and greater surface charge, the PA membrane could separate binary mixtures of protocatechuic/salicylic acid and 4-hydroxybenzoic/salicylic acid at pH 9.0, with separation factors of 1.81 and 1.78, respectively. These results provide a greater understanding of solute/membrane interactions and their effect on the penetration of phenolic acids through polymeric ultrafiltration membranes.

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Geiger, Benjamin. "Microfilament-membrane interaction." Trends in Biochemical Sciences 10, no. 11 (November 1985): 456–61. http://dx.doi.org/10.1016/0968-0004(85)90031-3.

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Murali, J., D. Koteeswari, J. M. Rifkind, and R. Jayakumar. "Amyloid insulin interaction with erythrocytes." Biochemistry and Cell Biology 81, no. 1 (January 1, 2003): 51–59. http://dx.doi.org/10.1139/o03-009.

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Erythrocyte membrane interactions with insulin fibrils (amyloid) have been investigated using centrifugation, fluorescence spectroscopy, light scattering, and flow cytometric techniques. The results indicate that insulin fibrils are having moderate affinity to erythrocyte membrane. However, analysis of the apparent dissociation constants of human erythrocyte membranes (leaky and resealed vesicles) with amyloid insulin reveal that the insulin binding is drastically reduced on attaining the fibrillar state compared with native insulin. To understand the role of insulin receptors on erythrocytes binding to amyloid, we have studied the interaction of biotinylated forms of denatured and amyloidic insulin with erythrocytes. FITC-streptavidin was used as a counter staining in flow cytometry measurements. We found that insulin fibrils bind 10 times more with erythrocyte membranes than with amylin and denatured insulin.Key words: insulin amyloid, erythrocyte membrane, amyloid binding, flow cytometry, dissociation constant.

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Ishida, Tatsuhiro, and Hiroshi Kiwada. "Interaction of Liposomes with Cell Membrane." MEMBRANE 32, no. 1 (2007): 18–24. http://dx.doi.org/10.5360/membrane.32.18.

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Luck, Meike, Markus Fischer, Maximilian Werle, Holger A. Scheidt, and Peter Müller. "Impact of Selected Small-Molecule Kinase Inhibitors on Lipid Membranes." Pharmaceuticals 14, no. 8 (July 29, 2021): 746. http://dx.doi.org/10.3390/ph14080746.

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Small-molecule protein kinase inhibitors are used for the treatment of various diseases. Although their effect(s) on the respective kinase are generally quite well understood, surprisingly, their interaction with membranes is only barely investigated; even though these drugs necessarily come into contact with the plasma and intracellular membranes. Using biophysical methods such as NMR, ESR, and fluorescence spectroscopy in combination with lipid vesicles, we studied the membrane interaction of the kinase inhibitors sunitinib, erlotinib, idelalisib, and lenvatinib; these drugs are characterized by medium log p values, a parameter reflecting the overall hydrophobicity of the molecules, which is one important parameter to predict the interaction with lipid membranes. While all four molecules tend to embed in a similar region of the lipid membrane, their presence has different impacts on membrane structure and dynamics. Most notably, sunitinib, exhibiting the lowest log p value of the four inhibitors, effectively influences membrane integrity, while the others do not. This shows that the estimation of the effect of drug molecules on lipid membranes can be rather complex. In this context, experimental studies on lipid membranes are necessary to (i) identify drugs that may disturb membranes and (ii) characterize drug–membrane interactions on a molecular level. Such knowledge is important for understanding the efficacy and potential side effects of respective drugs.

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Dick, Robert A., Marilia Barros, Danni Jin, Mathias Lösche, and Volker M. Vogt. "Membrane Binding of the Rous Sarcoma Virus Gag Protein Is Cooperative and Dependent on the Spacer Peptide Assembly Domain." Journal of Virology 90, no. 5 (December 16, 2015): 2473–85. http://dx.doi.org/10.1128/jvi.02733-15.

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ABSTRACTThe principles underlying membrane binding and assembly of retroviral Gag proteins into a lattice are understood. However, little is known about how these processes are related. Using purified Rous sarcoma virus Gag and Gag truncations, we studied the interrelation of Gag-Gag interaction and Gag-membrane interaction. Both by liposome binding and by surface plasmon resonance on a supported bilayer, Gag bound to membranes much more tightly than did matrix (MA), the isolated membrane binding domain. In principle, this difference could be explained either by protein-protein interactions leading to cooperativity in membrane binding or by the simultaneous interaction of the N-terminal MA and the C-terminal nucleocapsid (NC) of Gag with the bilayer, since both are highly basic. However, we found that NC was not required for strong membrane binding. Instead, the spacer peptide assembly domain (SPA), a putative 24-residue helical sequence comprising the 12-residue SP segment of Gag and overlapping the capsid (CA) C terminus and the NC N terminus, was required. SPA is known to be critical for proper assembly of the immature Gag lattice. A single amino acid mutation in SPA that abrogates assemblyin vitrodramatically reduced binding of Gag to liposomes.In vivo, plasma membrane localization was dependent on SPA. Disulfide cross-linking based on ectopic Cys residues showed that the contacts between Gag proteins on the membrane are similar to the known contacts in virus-like particles. Taken together, we interpret these results to mean that Gag membrane interaction is cooperative in that it depends on the ability of Gag to multimerize.IMPORTANCEThe retroviral structural protein Gag has three major domains. The N-terminal MA domain interacts directly with the plasma membrane (PM) of cells. The central CA domain, together with immediately adjoining sequences, facilitates the assembly of thousands of Gag molecules into a lattice. The C-terminal NC domain interacts with the genome, resulting in packaging of viral RNA. For assemblyin vitrowith purified Gag, in the absence of membranes, binding of NC to nucleic acid somehow facilitates further Gag-Gag interactions that lead to formation of the Gag lattice. The contributions of MA-mediated membrane binding to virus particle assembly are not well understood. Here, we report that in the absence of nucleic acid, membranes provide a platform that facilitates Gag-Gag interactions. This study demonstrates that the binding of Gag, but not of MA, to membranes is cooperative and identifies SPA as a major factor that controls this cooperativity.

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Ko, Ting Hsuan, and Yi-Fan Chen. "Correlation between the In-Plane Critical Behavior and Out-of-Plane Interaction of Ternary Lipid Membranes." Membranes 13, no. 1 (December 21, 2022): 6. http://dx.doi.org/10.3390/membranes13010006.

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Liquid-liquid phase-separating lipid membranes belong to the 2-D Ising universality class. While their in-plane critical behaviors are well studied, how the behaviors modulate out-of-plane interactions is rarely explored, despite its profound implications for biomembranes and 2-D ferromagnets. Here, we examine how the interlayer interaction, manifested as membrane fusion, is affected by the membranes’ critical fluctuations. Remarkably, the critical fluctuations suppress membrane fusion, suggesting a correlation between critical behaviors and interlayer interactions for 2-D Ising systems.

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Ronco, C., M. Feriani, S. Chiaramonte, A. Fabris, A. Brendolan, L. Bragantini, G. Pietribiasi, S. Meli, and G. La Greca. "Biocompatibility of Synthetic Membranes and Blood-Membrane Interaction." International Journal of Artificial Organs 10, no. 3 (May 1987): 205. http://dx.doi.org/10.1177/039139888701000314.

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Aragón-Muriel, Alberto, Yamil Liscano, David Morales-Morales, Dorian Polo-Cerón, and Jose Oñate-Garzón. "A Study of the Interaction of a New Benzimidazole Schiff Base with Synthetic and Simulated Membrane Models of Bacterial and Mammalian Membranes." Membranes 11, no. 6 (June 16, 2021): 449. http://dx.doi.org/10.3390/membranes11060449.

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Biological membranes are complex dynamic systems composed of a great variety of carbohydrates, lipids, and proteins, which together play a pivotal role in the protection of organisms and through which the interchange of different substances is regulated in the cell. Given the complexity of membranes, models mimicking them provide a convenient way to study and better understand their mechanisms of action and their interactions with biologically active compounds. Thus, in the present study, a new Schiff base (Bz-Im) derivative from 2-(m-aminophenyl)benzimidazole and 2,4-dihydroxybenzaldehyde was synthesized and characterized by spectroscopic and spectrometric techniques. Interaction studies of (Bz-Im) with two synthetic membrane models prepared with 1,2-dimyristoyl-sn-glycero-3-phosphocholine (DMPC) and DMPC/1,2-dimyristoyl-sn-glycero-3-phosphoglycerol (DMPG) 3:1 mixture, imitating eukaryotic and prokaryotic membranes, respectively, were performed by applying differential scanning calorimetry (DSC). Molecular dynamics simulations were also developed to better understand their interactions. In vitro and in silico assays provided approaches to understand the effect of Bz-Im on these lipid systems. The DSC results showed that, at low compound concentrations, the effects were similar in both membrane models. By increasing the concentration of Bz-Im, the DMPC/DMPG membrane exhibited greater fluidity as a result of the interaction with Bz-Im. On the other hand, molecular dynamics studies carried out on the erythrocyte membrane model using the phospholipids POPE (1-palmitoyl-2-oleoyl-sn-glycero-3-phosphoethanolamine), SM (N-(15Z-tetracosenoyl)-sphing-4-enine-1-phosphocholine), and POPC (1-palmitoyl-2-oleoyl-sn-glycero-3-phosphocholine) revealed that after 30 ns of interaction, both hydrophobic interactions and hydrogen bonds were responsible for the affinity of Bz-Im for PE and SM. The interactions of the imine with POPG (1-Palmitoyl-2-Oleoyl-sn-Glycero-3-Phosphoglycerol) in the E. coli membrane model were mainly based on hydrophobic interactions.

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Crosio, Matías A., Matías A. Via, Candelaria I. Cámara, Agustin Mangiarotti, Mario G. Del Pópolo, and Natalia Wilke. "Interaction of a Polyarginine Peptide with Membranes of Different Mechanical Properties." Biomolecules 9, no. 10 (October 18, 2019): 625. http://dx.doi.org/10.3390/biom9100625.

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The membrane translocation efficiency of cell penetrating peptides (CPPs) has been largely studied, and poly-arginines have been highlighted as particularly active CPPs, especially upon negatively charged membranes. Here we inquire about the influence of membrane mechanical properties in poly-arginine adsorption, penetration and translocation, as well as the subsequent effect on the host membrane. For this, we selected anionic membranes exhibiting different rigidity and fluidity, and exposed them to the nona-arginine KR9C. Three different membrane compositions were investigated, all of them having 50% of the anionic lipid 1,2-dioleoyl-sn-glycero-3-phospho-(1’-rac-glycerol) (DOPG), thus, ensuring a high affinity of the peptide for membrane surfaces. The remaining 50% was a saturated PC (1,2-dipalmitoyl-sn-glycero-3-phosphocholine, DPPC), an unsaturated PC (1,2-dioleoyl-sn-glycero-3-phosphocholine, DOPC) or a mixture of DOPC with cholesterol. Peptide-membrane interactions were studied using four complementary models for membranes: Langmuir monolayers, Large Unilamellar Vesicles, Black Lipid Membranes and Giant Unilamellar Vesicles. The patterns of interaction of KR9C varied within the different membrane compositions. The peptide strongly adsorbed on membranes with cholesterol, but did not incorporate or translocate them. KR9C stabilized phase segregation in DPPC/DOPG films and promoted vesicle rupture. DOPC/DOPG appeared like the better host for peptide translocation: KR9C adsorbed, inserted and translocated these membranes without breaking them, despite softening was observed.

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Weber-Boyvat, Marion, Hongxia Zhao, Nina Aro, Qiang Yuan, Konstantin Chernov, Johan Peränen, Pekka Lappalainen, and Jussi Jäntti. "A conserved regulatory mode in exocytic membrane fusion revealed by Mso1p membrane interactions." Molecular Biology of the Cell 24, no. 3 (February 2013): 331–41. http://dx.doi.org/10.1091/mbc.e12-05-0415.

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Sec1/Munc18 family proteins are important components of soluble N-ethylmaleimide–sensitive factor attachment protein receptor (SNARE) complex–mediated membrane fusion processes. However, the molecular interactions and the mechanisms involved in Sec1p/Munc18 control and SNARE complex assembly are not well understood. We provide evidence that Mso1p, a Sec1p- and Sec4p-binding protein, interacts with membranes to regulate membrane fusion. We identify two membrane-binding sites on Mso1p. The N-terminal region inserts into the lipid bilayer and appears to interact with the plasma membrane, whereas the C-terminal region of the protein binds phospholipids mainly through electrostatic interactions and may associate with secretory vesicles. The Mso1p membrane interactions are essential for correct subcellular localization of Mso1p–Sec1p complexes and for membrane fusion in Saccharomyces cerevisiae. These characteristics are conserved in the phosphotyrosine-binding (PTB) domain of β-amyloid precursor protein–binding Mint1, the mammalian homologue of Mso1p. Both Mint1 PTB domain and Mso1p induce vesicle aggregation/clustering in vitro, supporting a role in a membrane-associated process. The results identify Mso1p as a novel lipid-interacting protein in the SNARE complex assembly machinery. Furthermore, our data suggest that a general mode of interaction, consisting of a lipid-binding protein, a Rab family GTPase, and a Sec1/Munc18 family protein, is important in all SNARE-mediated membrane fusion events.

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Sharma, Neha, Pooja Gusain, Tsuyoshi Yoda, and Masahiro Takagi. "1P219 Interaction Of Warm-Sensing Chemical Capsaicin with the Biomimetic Membranes(13B. Biological & Artifical membrane: Dynamics,Poster)." Seibutsu Butsuri 53, supplement1-2 (2013): S142. http://dx.doi.org/10.2142/biophys.53.s142_2.

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Watala, Cezary, Krzysztof Gwoździński, Elżbieta Pluskota, Tadeusz Pietrucha, Bogdan Walkowiak, Zygmunt trojanowski, and Czesław S. Cierniewski. "Diabetes Mellitus Alters the Effect of Peptide and Protein Ligands on Membrane Fluidity of Blood Platelets." Thrombosis and Haemostasis 75, no. 01 (1996): 147–53. http://dx.doi.org/10.1055/s-0038-1650235.

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SummaryThe increased nonenzymatic glycosylation of platelet membrane proteins has been suggested to underlie platelet hypersensitivity in diabetes and the relationship of this to the reduced membrane lipid fluidity has been reported. As the modulation in membrane fluidity may determine the degree of accessibility of membrane receptors, the consequent alterations in membrane lipid-protein interactions in diabetes mellitus may also underlie the differentiated effects of various thrombotic and fibrinolytic agents on platelet membrane lipid bilayer.In the present study we employed electron paramagnetic resonance and fluorescence spectroscopy to explore the ligand-induced platelet membrane fluidity changes in diabetic state, i.e. under conditions when the membrane architecture is considerably altered.The yield of the excimer formation of pyrenemaleimide (PM), which depends directly upon the collisional rate and distances between molecules, was elevated in diabetic platelet membranes, thus pointing to the occurrence of some constraints in the structure/conformation of platelet membrane proteins in diabetes mellitus. Such an immobilization of PM was accompanied by the significant elevation in membrane protein gly-cation in diabetic platelets. The effects of various interacting ligands on platelet membrane fluidity were significantly lower in diabetic platelets, and the differences were much more distinct at the lower depths of a lipid bilayer. Nevertheless, the alterations in membrane lipid fluidity observed upon the interaction of a given ligand occurred with an approximately equal frequency in control and diabetic platelets. Moreover, the probability that these alterations were less profound in diabetic platelets was the same for all types of ligands studied. In diabetic patients the interaction of RGDS and tissue-type plasminogen activator with platelet membranes resulted in much smaller reductions of the h+1/h0 parameters in 5-DOXYL-Ste acid-labelled platelets, thus indicating a lesser rigidization of membrane lipid bilayer in diabetes. Likewise, the fluidizing effect of both fibrinogen itself and fibrinogen-derived peptides containing γ-chain carboxy-terminal sequence H-12-V was less pronounced in diabetic platelet membranes.

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Gonçalves, Sónia, and Nuno C. Santos. "Membrane–Peptide Interactions: From Basics to Current Applications 2.0." International Journal of Molecular Sciences 24, no. 8 (April 13, 2023): 7202. http://dx.doi.org/10.3390/ijms24087202.

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The interaction between peptides and biological membranes is of fundamental importance in the mechanism of numerous membrane-mediated cellular processes, including antimicrobial peptide action, hormone–receptor interactions, drug bioavailability across the blood–brain barrier, and viral fusion processes [...]

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Singh, Pradeep Kumar, Søren S. R. Bohr, and Nikos S. Hatzakis. "Direct Observation of Sophorolipid Micelle Docking in Model Membranes and Cells by Single Particle Studies Reveals Optimal Fusion Conditions." Biomolecules 10, no. 9 (September 7, 2020): 1291. http://dx.doi.org/10.3390/biom10091291.

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Sophorolipids (SLs) are naturally produced glycolipids that acts as drug delivery for a spectrum of biomedical applications, including as an antibacterial antifungal and anticancer agent, where they induce apoptosis selectively in cancerous cells. Despite their utility, the mechanisms underlying their membrane interactions, and consequently cell entry, remains unknown. Here, we combined a single liposome assay to observe directly and quantify the kinetics of interaction of SL micelles with model membrane systems, and single particle studies on live cells to record their interaction with cell membranes and their cytotoxicity. Our single particle readouts revealed several repetitive docking events on individual liposomes and quantified how pH and membrane charges, which are known to vary in cancer cells, affect the docking of SL micelles on model membranes. Docking of sophorolipids micelles was found to be optimal at pH 6.5 and for membranes with −5% negatively charge lipids. Single particle studies on mammalian cells reveled a two-fold increased interaction on Hela cells as compared to HEK-293 cells. This is in line with our cell viability readouts recording an approximate two-fold increased cytotoxicity by SLs interactions for Hela cells as compared to HEK-293 cells. The combined in vitro and cell assays thus support the increased cytotoxicity of SLs on cancer cells to originate from optimal charge and pH interactions between membranes and SL assemblies. We anticipate studies combining quantitative single particle studies on model membranes and live cell may reveal hitherto unknown molecular insights on the interactions of sophorolipid and additional nanocarriers mechanism.

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Angarola, Brittany, and Shawn M. Ferguson. "Coordination of Rheb lysosomal membrane interactions with mTORC1 activation." F1000Research 9 (May 27, 2020): 450. http://dx.doi.org/10.12688/f1000research.22367.1.

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A complex molecular machinery converges on the surface of lysosomes to ensure that the growth-promoting signaling mediated by mechanistic target of rapamycin complex 1 (mTORC1) is tightly controlled by the availability of nutrients and growth factors. The final step in this activation process is dependent on Rheb, a small GTPase that binds to mTOR and allosterically activates its kinase activity. Here we review the mechanisms that determine the subcellular localization of Rheb (and the closely related RhebL1 protein) as well as the significance of these mechanisms for controlling mTORC1 activation. In particular, we explore how the relatively weak membrane interactions conferred by C-terminal farnesylation are critical for the ability of Rheb to activate mTORC1. In addition to supporting transient membrane interactions, Rheb C-terminal farnesylation also supports an interaction between Rheb and the δ subunit of phosphodiesterase 6 (PDEδ). This interaction provides a potential mechanism for targeting Rheb to membranes that contain Arl2, a small GTPase that triggers the release of prenylated proteins from PDEδ. The minimal membrane targeting conferred by C-terminal farnesylation of Rheb and RhebL1 distinguishes them from other members of the Ras superfamily that possess additional membrane interaction motifs that work with farnesylation for enrichment on the specific subcellular membranes where they engage key effectors. Finally, we highlight diversity in Rheb membrane targeting mechanisms as well as the potential for alternative mTORC1 activation mechanisms across species.

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Wang, Xiaofeng, Zhuoran Li, and Qingshan Yang. "Numerical Studies on the Air–Membrane Interaction of ETFE Cushions." International Journal of Structural Stability and Dynamics 21, no. 05 (March 3, 2021): 2150071. http://dx.doi.org/10.1142/s0219455421500711.

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Inflated membranes are popularly used in civil and aerospace engineering. They are flexible and their behaviors are featured by the interaction between the inner air pressure and deformation of the enveloping membrane (air–membrane interaction) which has not yet received attention in the literature. This paper aims at studying the air–membrane interaction and its influence on the static and dynamic properties of an inflated membrane by numerically analyzing a square ETFE (ethylene–tetrafluoroethylene) cushion. To account for the air–membrane interaction, the inner air was regarded as a linear potential fluid in developing the governing equations. The finite element model was derived from the discretized equations and verified through comparison with experimental results and those in the literature. Thereafter, the air–membrane interaction and its variation with influencing factors were investigated in the static and dynamic analysis by comparing results from the verified finite element model with the numerical solutions where the inner air was treated as the traction boundary conditions of the enveloping membrane. Results of this study indicate that (1) air–membrane interaction becomes more prominent with increasing external load and is gradually weakened with a rise in the frequency order; (2) air–membrane interaction makes the top membrane joined with the bottom membrane in the deformation and vibration; and (3) air–membrane interaction is strengthened with an increase in the initial inner pressure or geometric dimensions, but weakened when the membrane thickness or rise–span ratio increases. The present research is helpful to the understanding of the role the inner air plays in the behavior of inflated membranes, and may therefore improve the accuracy in analysis and the rationality in the design.

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London, Erwin. "Diphtheria toxin: membrane interaction and membrane translocation." Biochimica et Biophysica Acta (BBA) - Reviews on Biomembranes 1113, no. 1 (March 1992): 25–51. http://dx.doi.org/10.1016/0304-4157(92)90033-7.

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Denieva, Zaret G., Valerij S. Sokolov, and Oleg V. Batishchev. "HIV-1 Gag Polyprotein Affinity to the Lipid Membrane Is Independent of Its Surface Charge." Biomolecules 14, no. 9 (August 29, 2024): 1086. http://dx.doi.org/10.3390/biom14091086.

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The binding of the HIV-1 Gag polyprotein to the plasma membrane is a critical step in viral replication. The association with membranes depends on the lipid composition, but its mechanisms remain unclear. Here, we report the binding of non-myristoylated Gag to lipid membranes of different lipid compositions to dissect the influence of each component. We tested the contribution of phosphatidylserine, PI(4,5)P2, and cholesterol to membrane charge density and Gag affinity to membranes. Taking into account the influence of the membrane surface potential, we quantitatively characterized the adsorption of the protein onto model lipid membranes. The obtained Gag binding constants appeared to be the same regardless of the membrane charge. Furthermore, Gag adsorbed on uncharged membranes, suggesting a contribution of hydrophobic forces to the protein–lipid interaction. Charge–charge interactions resulted in an increase in protein concentration near the membrane surface. Lipid-specific interactions were observed in the presence of cholesterol, resulting in a two-fold increase in binding constants. The combination of cholesterol with PI(4,5)P2 showed cooperative effects on protein adsorption. Thus, we suggest that the affinity of Gag to lipid membranes results from a combination of electrostatic attraction to acidic lipids, providing different protein concentrations near the membrane surface, and specific hydrophobic interactions.

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Kremkow, Jan, Meike Luck, Daniel Huster, Peter Müller, and Holger A. Scheidt. "Membrane Interaction of Ibuprofen with Cholesterol-Containing Lipid Membranes." Biomolecules 10, no. 10 (September 28, 2020): 1384. http://dx.doi.org/10.3390/biom10101384.

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Deciphering the membrane interaction of drug molecules is important for improving drug delivery, cellular uptake, and the understanding of side effects of a given drug molecule. For the anti-inflammatory drug ibuprofen, several studies reported contradictory results regarding the impact of ibuprofen on cholesterol-containing lipid membranes. Here, we investigated membrane localization and orientation as well as the influence of ibuprofen on membrane properties in POPC/cholesterol bilayers using solid-state NMR spectroscopy and other biophysical assays. The presence of ibuprofen disturbs the molecular order of phospholipids as shown by alterations of the 2H and 31P-NMR spectra of the lipids, but does not lead to an increased membrane permeability or changes of the phase state of the bilayer. 1H MAS NOESY NMR results demonstrate that ibuprofen adopts a mean position in the upper chain/glycerol region of the POPC membrane, oriented with its polar carbonyl group towards the aqueous phase. This membrane position is only marginally altered in the presence of cholesterol. A previously reported result that ibuprofen is expelled from the membrane interface in cholesterol-containing DMPC bilayers could not be confirmed.

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Naparlo, Katarzyna, Grzegorz Bartosz, Ireneusz Stefaniuk, Bogumil Cieniek, Miroslaw Soszynski, and Izabela Sadowska-Bartosz. "Interaction of Catechins with Human Erythrocytes." Molecules 25, no. 6 (March 24, 2020): 1456. http://dx.doi.org/10.3390/molecules25061456.

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The aim of this study was to characterize the interaction of chosen catechins ((+)-catechin, (−)-epigallocatechin (EGC), and (−)-epigallocatechin gallate (EGCG)) with human erythrocytes and their protective effects against oxidative damage of erythrocytes. Uptake of the catechins by erythrocytes was studied by fluorimetry, their interaction with erythrocyte membrane was probed by changes in erythrocyte osmotic fragility and in membrane fluidity evaluated with spin labels, while protection against oxidative damage was assessed by protection against hemolysis induced by permanganate and protection of erythrocyte membranes against lipid peroxidation and protein thiol group oxidation. Catechin uptake was similar for all the compounds studied. Accumulation of catechins in the erythrocyte membrane was demonstrated by the catechin-induced increase in osmotic resistance and rigidification of the erythrocyte membrane detected by spin labels 5-doxyl stearic acid and 16-doxyl stearic acid. (−)-Epigallocatechin and EGCG inhibited erythrocyte acetylcholinesterase (mixed-type inhibition). Catechins protected erythrocytes against permanganate-induced hemolysis, oxidation of erythrocyte protein thiol groups, as well as membrane lipid peroxidation. These results contribute to the knowledge of the beneficial effects of catechins present in plant-derived food and beverages.

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Wang, Yuane, Xuankang Mou, Yongyun Ji, Fan Pan, and Shiben Li. "Interaction of Macromolecular Chain with Phospholipid Membranes in Solutions: A Dissipative Particle Dynamics Simulation Study." Molecules 28, no. 15 (July 31, 2023): 5790. http://dx.doi.org/10.3390/molecules28155790.

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The interaction between macromolecular chains and phospholipid membranes in aqueous solution was investigated using dissipative particle dynamics simulations. Two cases were considered, one in which the macromolecular chains were pulled along parallel to the membrane surfaces and another in which they were pulled vertical to the membrane surfaces. Several parameters, including the radius of gyration, shape factor, particle number, and order parameter, were used to investigate the interaction mechanisms during the dynamics processes by adjusting the pulling force strength of the chains. In both cases, the results showed that the macromolecular chains undergo conformational transitions from a coiled to a rod-like structure. Furthermore, the simulations revealed that the membranes can be damaged and repaired during the dynamic processes. The role of the pulling forces and the adsorption interactions between the chains and membranes differed in the parallel and perpendicular pulling cases. These findings contribute to our understanding of the interaction mechanisms between macromolecules and membranes, and they may have potential applications in biology and medicine.

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SHIMONAKA, Hiroyuki, and Michio YAMAMOTO. "Interaction between anesthetics and biological membranes." membrane 11, no. 1 (1986): 22–32. http://dx.doi.org/10.5360/membrane.11.22.

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Sani, N. A. A., W. J. Lau, and A. F. Ismail. "Influence of polymer concentration in casting solution and solvent-solute-membrane interactions on performance of polyphenylsulfone (PPSU) nanofiltration membrane in alcohol solvents." Journal of Polymer Engineering 34, no. 6 (August 1, 2014): 489–500. http://dx.doi.org/10.1515/polyeng-2014-0038.

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Abstract In this work, the performances of solvent resistant nanofiltration (SRNF) membranes made of polyphenylsulfone (PPSU) were evaluated with respect to alcohol solvent (methanol, ethanol and isopropanol) flux and dye rejection. The experimental results showed that the solvent flux decreased while dye rejection increased with increasing polymer concentration in the casting solution from 17 wt% to 25 wt%. Apart from molecular size of the solute and viscosity of the solvent, the affinity between the solvent and the membrane was also confirmed to play a significant role in affecting the transport rate of the solvent through the membrane. With respect to the effect of solvent properties and solute size on the dye rejection of solvent-dye mixtures, it was found that the variation of dye rejection is governed by solvent-solute-membrane interactions. The solvent-solute interaction causes the same solute to have different solute size in each tested solvents, whereas the solvent-membrane interaction would result in a change in membrane pore size, leading to different separation efficiency. However, it must pointed out that solvent-membrane interaction is more pronounced compared to solvent-solute interaction, as the dye rejection of ethanol solution is reportedly higher than that of methanol, even though the size of solute in ethanol is smaller compared to its size in methanol.

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Appelman, Monique D., Marion J. D. Robin, Esther W. M. Vogels, Christie Wolzak, Winnie G. Vos, Harmjan R. Vos, Robert M. Van Es, Boudewijn M. T. Burgering, and Stan F. J. Van de Graaf. "The Lipid Raft Component Stomatin Interacts with the Na+ Taurocholate Cotransporting Polypeptide (NTCP) and Modulates Bile Salt Uptake." Cells 9, no. 4 (April 16, 2020): 986. http://dx.doi.org/10.3390/cells9040986.

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The sodium taurocholate cotransporting polypeptide (NTCP) is expressed at the basolateral membrane of hepatocytes, where it mediates the uptake of conjugated bile acids and forms the hepatocyte entry receptor for the hepatitis B and D virus. Here, we aimed to identify novel protein–protein interactions that could play a role in the regulation of NTCP. To this end, NTCP was precipitated from HA-tagged hNTCP-expressing HepG2 cells, and chloride channel CLIC-like 1 (CLCC1) and stomatin were identified as interacting proteins by mass spectrometry. Interaction was confirmed by co-immunoprecipitation. NTCP, CLCC1 and stomatin were found at the plasma membrane in lipid rafts, as demonstrated by a combination of immunofluorescence, cell surface biotinylation and isolation of detergent-resistant membranes. Neither CLCC1 overexpression nor its knockdown had an effect on NTCP function. However, both stomatin overexpression and knockdown increased NTCP-mediated taurocholate uptake while NTCP abundance at the plasma membrane was only increased in stomatin depleted cells. These findings identify stomatin as an interactor of NTCP and show that the interaction modulates bile salt transport.

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Insausti, Sara, Miguel Garcia-Porras, Johana Torralba, Izaskun Morillo, Ander Ramos-Caballero, Igor de la Arada, Beatriz Apellaniz, et al. "Functional Delineation of a Protein–Membrane Interaction Hotspot Site on the HIV-1 Neutralizing Antibody 10E8." International Journal of Molecular Sciences 23, no. 18 (September 15, 2022): 10767. http://dx.doi.org/10.3390/ijms231810767.

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Antibody engagement with the membrane-proximal external region (MPER) of the envelope glycoprotein (Env) of HIV-1 constitutes a distinctive molecular recognition phenomenon, the full appreciation of which is crucial for understanding the mechanisms that underlie the broad neutralization of the virus. Recognition of the HIV-1 Env antigen seems to depend on two specific features developed by antibodies with MPER specificity: (i) a large cavity at the antigen-binding site that holds the epitope amphipathic helix; and (ii) a membrane-accommodating Fab surface that engages with viral phospholipids. Thus, besides the main Fab–peptide interaction, molecular recognition of MPER depends on semi-specific (electrostatic and hydrophobic) interactions with membranes and, reportedly, on specific binding to the phospholipid head groups. Here, based on available cryo-EM structures of Fab–Env complexes of the anti-MPER antibody 10E8, we sought to delineate the functional antibody–membrane interface using as the defining criterion the neutralization potency and binding affinity improvements induced by Arg substitutions. This rational, Arg-based mutagenesis strategy revealed the position-dependent contribution of electrostatic interactions upon inclusion of Arg-s at the CDR1, CDR2 or FR3 of the Fab light chain. Moreover, the contribution of the most effective Arg-s increased the potency enhancement induced by inclusion of a hydrophobic-at-interface Phe at position 100c of the heavy chain CDR3. In combination, the potency and affinity improvements by Arg residues delineated a protein–membrane interaction site, whose surface and position support a possible mechanism of action for 10E8-induced neutralization. Functional delineation of membrane-interacting patches could open new lines of research to optimize antibodies of therapeutic interest that target integral membrane epitopes.

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Yeh, Vivien, and Boyan B. Bonev. "Solid state NMR of membrane proteins: methods and applications." Biochemical Society Transactions 49, no. 4 (August 16, 2021): 1505–13. http://dx.doi.org/10.1042/bst20200070.

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Membranes of cells are active barriers, in which membrane proteins perform essential remodelling, transport and recognition functions that are vital to cells. Membrane proteins are key regulatory components of cells and represent essential targets for the modulation of cell function and pharmacological intervention. However, novel folds, low molarity and the need for lipid membrane support present serious challenges to the characterisation of their structure and interactions. We describe the use of solid state NMR as a versatile and informative approach for membrane and membrane protein studies, which uniquely provides information on structure, interactions and dynamics of membrane proteins. High resolution approaches are discussed in conjunction with applications of NMR methods to studies of membrane lipid and protein structure and interactions. Signal enhancement in high resolution NMR spectra through DNP is discussed as a tool for whole cell and interaction studies.

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Tiruppathi, Chinnaswamy, David H. Alpers, and Bellur Seetharam. "Interaction of Intestinal Disaccharidases with Phospholipids." Journal of Pediatric Gastroenterology and Nutrition 4, no. 6 (December 1985): 965–70. http://dx.doi.org/10.1002/j.1536-4801.1985.tb08994.x.

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Although the rat intestinal brush border disaccharidases are the most easily solubilized protein components, the nature of the lipid‐protein interactions in the membrane is incompletely understood. Phospholipid vesicles were prepared using the lecithin fraction from brush border membranes and synthetic lecithins. Addition of cholesterol to brush border lecithins enhanced the binding of disaccharidases, but not of alkaline phosphatase. The addition of cholesterol to synthetic lecithin vesicles enhanced the binding of disaccharidases only when added above the transition temperature of the lecithin used. The maximal effect occurred at an equimolar ratio of lecithin to cholesterol. Binding of disaccharidases to phospholipid vesicles was independent of charge or the nature of the polar head group, and the enzyme was inserted so that the catalytic domain was excluded from the lipid matrix. These results demonstrate that membrane attachment of disaccharidases is hydrophobic, involving primarily fatty acyl chains and an interaction with cholesterol. The membrane interaction does not seem to affect enzyme activity.

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Suetsugu, Shiro, Shusaku Kurisu, and Tadaomi Takenawa. "Dynamic Shaping of Cellular Membranes by Phospholipids and Membrane-Deforming Proteins." Physiological Reviews 94, no. 4 (October 2014): 1219–48. http://dx.doi.org/10.1152/physrev.00040.2013.

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All cellular compartments are separated from the external environment by a membrane, which consists of a lipid bilayer. Subcellular structures, including clathrin-coated pits, caveolae, filopodia, lamellipodia, podosomes, and other intracellular membrane systems, are molded into their specific submicron-scale shapes through various mechanisms. Cells construct their micro-structures on plasma membrane and execute vital functions for life, such as cell migration, cell division, endocytosis, exocytosis, and cytoskeletal regulation. The plasma membrane, rich in anionic phospholipids, utilizes the electrostatic nature of the lipids, specifically the phosphoinositides, to form interactions with cytosolic proteins. These cytosolic proteins have three modes of interaction: 1) electrostatic interaction through unstructured polycationic regions, 2) through structured phosphoinositide-specific binding domains, and 3) through structured domains that bind the membrane without specificity for particular phospholipid. Among the structured domains, there are several that have membrane-deforming activity, which is essential for the formation of concave or convex membrane curvature. These domains include the amphipathic helix, which deforms the membrane by hemi-insertion of the helix with both hydrophobic and electrostatic interactions, and/or the BAR domain superfamily, known to use their positively charged, curved structural surface to deform membranes. Below the membrane, actin filaments support the micro-structures through interactions with several BAR proteins as well as other scaffold proteins, resulting in outward and inward membrane micro-structure formation. Here, we describe the characteristics of phospholipids, and the mechanisms utilized by phosphoinositides to regulate cellular events. We then summarize the precise mechanisms underlying the construction of membrane micro-structures and their involvements in physiological and pathological processes.

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HUANG, Huan, Friedhelm SCHROEDER, Mary K. ESTES, Tanya McPHERSON, and Judith M. BALL. "Interaction(s) of rotavirus non-structural protein 4 (NSP4) C-terminal peptides with model membranes." Biochemical Journal 380, no. 3 (June 15, 2004): 723–33. http://dx.doi.org/10.1042/bj20031789.

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Rotavirus is the major cause of dehydrating gastroenteritis in children and young animals. NSP4 (non-structural protein 4), a rotaviral non-structural glycoprotein and a peptide NSP4114–135 (DKLTTREIEQVELLKRIYDKLT), corresponding to NSP4 amino acids 114–135, induce diarrhoeal disease in a neonatal mouse model and interact with model membranes that mimic caveolae. Correlation of the mechanisms of diarrhoea induction and membrane interactions by NSP4 protein and peptide remain unclear. Several additional NSP4 peptides were synthesized and their interactions with membranes studied by (i) CD, (ii) a filtration-binding assay and (iii) a fluorescent molecule leakage assay. Model membranes that varied in lipid compositions and radius of curvature were utilized to determine the compositional and structural requirements for optimal interaction with the peptides of NSP4. Similar to the intact protein and NSP4114–135, peptides overlapping residues 114–135 had significantly higher affinities to membranes rich in negatively charged lipids, rich in cholesterol and with a high radius of curvature. In the leakage assay, small and large unilamellar vesicles loaded with the fluorophore/quencher pair 8-aminonaphthalene-1,3,6-trisulphonic acid disodium salt/p-xylene-bis-pyridinium bromide were incubated with the NSP4 peptides and monitored for membrane disruption by lipid reorganization or by pore formation. At a peptide concentration of 15 µM, none of the NSP4 peptides caused leakage. These results confirm that NSP4 interacts with caveolae-like membranes and the α-helical region of NSP4114–135 comprises a membrane interaction domain that does not induce membrane disruption at physiological concentrations.

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Voland, Petra, David L. Weeks, Elizabeth A. Marcus, Christian Prinz, George Sachs, and David Scott. "Interactions among the sevenHelicobacter pyloriproteins encoded by the urease gene cluster." American Journal of Physiology-Gastrointestinal and Liver Physiology 284, no. 1 (January 1, 2003): G96—G106. http://dx.doi.org/10.1152/ajpgi.00160.2002.

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Survival of Helicobacter pylori in acid depends on intrabacterial urease. This urease is a Ni2+-containing oligomeric heterodimer. Regulation of its activity and assembly is important for gastric habitation by this neutralophile. The gene complex encodes catalytic subunits ( ureA/B), an acid-gated urea channel ( ureI), and accessory assembly proteins ( ureE–H). With the use of yeast two-hybrid analysis for determining protein-protein interactions, UreF as bait identified four interacting sequences encoding UreH, whereas UreG as bait detected five UreE sequences. These results were confirmed by coimmunoprecipitation and β-galactosidase assays. Native PAGE immunoblotting of H. pylori inner membranes showed interaction of UreA/B with UreI, whereas UreI deletion mutants lacked this protein interaction. Deletion of ureE–H did not affect this interaction with UreI. Hence, the accessory proteins UreE/G and UreF/H form dimeric complexes and UreA/B form a membrane complex with UreI, perhaps enabling assembly of the urease apoenzyme at the membrane surface and immediate urea access to intrabacterial urease to allow rapid periplasmic neutralization.

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Cho, Nam-Joon, Kwang Ho Cheong, ChoongHo Lee, Curtis W. Frank, and Jeffrey S. Glenn. "Binding Dynamics of Hepatitis C Virus' NS5A Amphipathic Peptide to Cell and Model Membranes." Journal of Virology 81, no. 12 (April 11, 2007): 6682–89. http://dx.doi.org/10.1128/jvi.02783-06.

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ABSTRACT Membrane association of the hepatitis C virus NS5A protein is required for viral replication. This association is dependent on an N-terminal amphipathic helix (AH) within NS5A and is restricted to a subset of host cell intracellular membranes. The mechanism underlying this specificity is not known, but it may suggest a novel strategy for developing specific antiviral therapy. Here we have probed the mechanistic details of NS5A AH-mediated binding to both cell-derived and model membranes by use of biochemical membrane flotation and quartz crystal microbalance (QCM) with dissipation. With both assays, we observed AH-mediated binding to model lipid bilayers. When cell-derived membranes were coated on the quartz nanosensor, however, significantly more binding was detected, and the QCM-derived kinetic measurements suggested the existence of an interacting receptor in the target membranes. Biochemical flotation assays performed with trypsin-treated cell-derived membranes exhibited reduced AH-mediated membrane binding, while membrane binding of control cytochrome b5 remained unaffected. Similarly, trypsin treatment of the nanosensor coated with cellular membranes abolished AH peptide binding to the cellular membranes but did not affect the binding of a control lipid-binding peptide. These results therefore suggest that a protein plays a critical role in mediating and stabilizing the binding of NS5A's AH to its target membrane. These results also demonstrate the successful development of a new nanosensor technology ideal both for studying the interaction between a protein and its target membrane and for developing inhibitors of that interaction.

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Zhao, Hongxia, and Pekka Lappalainen. "A simple guide to biochemical approaches for analyzing protein–lipid interactions." Molecular Biology of the Cell 23, no. 15 (August 2012): 2823–30. http://dx.doi.org/10.1091/mbc.e11-07-0645.

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Eukaryotic cells contain many different membrane compartments with characteristic shapes, lipid compositions, and dynamics. A large fraction of cytoplasmic proteins associate with these membrane compartments. Such protein–lipid interactions, which regulate the subcellular localizations and activities of peripheral membrane proteins, are fundamentally important for a variety of cell biological processes ranging from cytoskeletal dynamics and membrane trafficking to intracellular signaling. Reciprocally, many membrane-associated proteins can modulate the shape, lipid composition, and dynamics of cellular membranes. Determining the exact mechanisms by which these proteins interact with membranes will be essential to understanding their biological functions. In this Technical Perspective, we provide a brief introduction to selected biochemical methods that can be applied to study protein–lipid interactions. We also discuss how important it is to choose proper lipid composition, type of model membrane, and biochemical assay to obtain reliable and informative data from the lipid-interaction mechanism of a protein of interest.

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Nawaz, Nighat, Roshan Ali, Muhammad Ali, Iain W. Manfield, Muhammad Kamran Taj, Mohammad Zahid Mustafa, and Simon G. Patching. "Microscale Thermophoresis Analysis of Membrane Proteins." Chemical Science International Journal 33, no. 2 (March 4, 2024): 25–45. http://dx.doi.org/10.9734/csji/2024/v33i2887.

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Microscale thermophoresis (MST) is an analytical technique for measuring biomolecular interactions. It is based on the physical phenomenon that particles move within temperature gradients, which is affected by their size, charge, hydration shell and conformation. The MST sample must contain a fluorescent target molecule used to observe the movement of particles, and this can be titrated with an unlabelled binding partner for quantifying the interaction. MST is highly sensitive, using relatively small amounts of sample, and it has no limitations on the size of the target biomolecule, on the affinity of the interaction or on the composition of the buffer and other sample components. This makes MST ideally suited to characterising interactions with membrane proteins, which can be studied in cell lysates, native membranes, solubilised in detergents or reconstituted in lipids. The intrinsic aromatic residues of membrane proteins have been used as the fluorophore for MST (label-free MST) or membrane proteins have been labelled with a range of fluorescent dyes or conjugated with fluorescent proteins (labelled MST). The different types of membrane proteins that have had biomolecular interactions characterised by MST include the SARS-CoV-2 spike protein, GPCRs and other receptors, sensor kinases, ion channels, aquaporins, and transport proteins.

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Xu, Yan, Victor E. Yushmanov, and Pei Tang. "NMR Studies of Drug Interaction with Membranes and Membrane-Associated Proteins." Bioscience Reports 22, no. 2 (April 1, 2002): 175–96. http://dx.doi.org/10.1023/a:1020182404940.

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This review focuses on the recent developments in the study of drug interactions with biological membranes and membrane-associated proteins using nuclear magnetic resonance (NMR) spectroscopy and other spectroscopic techniques. Emphasis is placed on a class of low-affinity neurological agents as exemplified by volatile general anesthetics and structurally related compounds. The technical aspects are reviewed of how to prepare membrane-mimetic systems and of NMR approaches that are either in current use or opening new prospects. A brief literature survey covers studies ranging from drug distribution in simplified lipid matrix to specific drug interaction with neuronal receptors reconstituted in complicated synthetic membrane systems.

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Olafiranye, Feyisayo, Win Kyaw, and Oladipupo Olafiranye. "Resolution of Dialyzer Membrane-Associated Thrombocytopenia with Use of Cellulose Triacetate Membrane: A Case Report." Case Reports in Medicine 2011 (2011): 1–3. http://dx.doi.org/10.1155/2011/134295.

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Blood and dialyzer membrane interaction can cause significant thrombocytopenia through the activation of complement system. The extent of this interaction determines the biocompatibility of the membrane. Although the newer synthetic membranes have been shown to have better biocompatibility profile than the cellulose-based membranes, little is known about the difference in biocompatibility between synthetic membrane and modified cellulose membrane. Herein, we report a case of a patient on hemodialysis who developed dialyzer-membrane-related thrombocytopenia with use of synthetic membrane (F200NR polysulfone). The diagnosis of dialyzer membrane-associated thrombocytopenia was suspected by the trend of platelet count before and after dialysis, and the absence of other possible causes of thrombocytopenia. We observed significant improvement in platelet count when the membrane was changed to modified cellulose membrane (cellulose triacetate). In patients at high risk for thrombocytopenia, the modified cellulose membrane could be a better alternative to the standard synthetic membranes during hemodialysis.

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YAMAMOTO, Eiji. "Interaction of Membrane Bound Proteins with Phosphoinositide-containing Membranes." Seibutsu Butsuri 61, no. 4 (2021): 253–54. http://dx.doi.org/10.2142/biophys.61.253.

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Vu, Anh T., Xinying Wang, S. Ranil Wickramasinghe, Bing Yu, Hua Yuan, Hailin Cong, Yongli Luo, and Jianguo Tang. "Inverse colloidal crystal membranes for hydrophobic interaction membrane chromatography." Journal of Separation Science 38, no. 16 (July 14, 2015): 2819–25. http://dx.doi.org/10.1002/jssc.201500295.

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Vu, Anh T., Xinying Wang, S. Ranil Wickramasinghe, Bing Yu, Hua Yuan, Hailin Cong, Yongli Luo, and Jianguo Tang. "Inverse colloidal crystal membranes for hydrophobic interaction membrane chromatography." Journal of Separation Science 38, no. 16 (August 2015): NA. http://dx.doi.org/10.1002/jssc.201570161.

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Vu, Anh T., Xinying Wang, S. Ranil Wickramasinghe, Bing Yu, Hua Yuan, Hailin Cong, Yongli Luo, and Jianguo Tang. "Inverse colloidal crystal membranes for hydrophobic interaction membrane chromatography." Journal of Separation Science 38, no. 17 (September 2015): NA. http://dx.doi.org/10.1002/jssc.201570171.

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Wenz, Christian, Coral Barbas, Ángeles López-Gonzálvez, Antonia Garcia, Fernando Benavente, Victoria Sanz-Nebot, Tim Blanc, et al. "Inverse colloidal crystal membranes for hydrophobic interaction membrane chromatography." Journal of Separation Science 38, no. 18 (September 2015): NA. http://dx.doi.org/10.1002/jssc.201570181.

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Journet, Laure, Alain Rigal, Claude Lazdunski, and Hélène Bénédetti. "Role of TolR N-Terminal, Central, and C-Terminal Domains in Dimerization and Interaction with TolA and TolQ." Journal of Bacteriology 181, no. 15 (August 1, 1999): 4476–84. http://dx.doi.org/10.1128/jb.181.15.4476-4484.1999.

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ABSTRACT The Tol-PAL system of Escherichia coli is a multiprotein system involved in maintaining the cell envelope integrity and is necessary for the import of some colicins and phage DNA into the bacterium. It is organized into two complexes, one near the outer membrane between TolB and PAL and one in the cytoplasmic membrane between TolA, TolQ, and TolR. In the cytoplasmic membrane, all of the Tol proteins have been shown to interact with each other. Cross-linking experiments have shown that the TolA transmembrane domain interacts with TolQ and TolR. Suppressor mutant analyses have localized the TolQ-TolA interaction to the first transmembrane domain of TolQ and have shown that the third transmembrane domain of TolQ interacts with the transmembrane domain of TolR. To get insights on the composition of the cytoplasmic membrane complex and its possible contacts with the outer membrane complex, we focused our attention on TolR. Cross-linking and immunoprecipitation experiments allowed the identification of Tol proteins interacting with TolR. The interactions of TolR with TolA and TolQ were confirmed, TolR was shown to dimerize, and the resulting dimer was shown to interact with TolQ. Deletion mutants of TolR were constructed, and they allowed us to determine the TolR domains involved in each interaction. The TolR transmembrane domain was shown to be involved in the TolA-TolR and TolQ-TolR interactions, while TolR central and C-terminal domains appeared to be involved in TolR dimerization. The role of the TolR C-terminal domain in the TolA-TolR interaction and its association with the membranes was also demonstrated. Furthermore, phenotypic studies clearly showed that the three TolR domains (N terminal, central, and C terminal) and the level of TolR production are important for colicin A import and for the maintenance of cell envelope integrity.

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Journal articles on the topic 'Membrane interaction'

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