Biochimica et biophysica acta. Biomembranes最新文献_第3页

Novel lipid-interaction motifs within the C-terminal domain of Septin10 from Schistosoma mansoni 曼氏血吸虫Septin10 C端结构域中的新型脂质相互作用基团

IF 2.8 3区生物学

Biochimica et biophysica acta. Biomembranes Pub Date : 2024-07-16 DOI: 10.1016/j.bbamem.2024.184371

Italo A. Cavini , Marina G. Fontes , Ana Eliza Zeraik , Jose L.S. Lopes , Ana Paula U. Araujo

{"title":"Novel lipid-interaction motifs within the C-terminal domain of Septin10 from Schistosoma mansoni","authors":"Italo A. Cavini , Marina G. Fontes , Ana Eliza Zeraik , Jose L.S. Lopes , Ana Paula U. Araujo","doi":"10.1016/j.bbamem.2024.184371","DOIUrl":"10.1016/j.bbamem.2024.184371","url":null,"abstract":"<div><p>Septins are cytoskeletal proteins and their interaction with membranes is crucial for their role in various cellular processes. Septins have polybasic regions (PB1 and PB2) which are important for lipid interaction. Earlier, we and others have highlighted the role of the septin C-terminal domain (CTD) to membrane interaction. However, detailed information on residues/group of residues important for such feature is lacking. In this study, we investigate the lipid-binding profile of <em>Schistosoma mansoni</em> Septin10 (<em>Sm</em>SEPT10) using PIP strip and Langmuir monolayer adsorption assays. Our findings highlight the CTD as the primary domain responsible for lipid interaction in <em>Sm</em>SEPT10, showing binding to phosphatidylinositol phosphates. <em>Sm</em>SEPT10 CTD contains a conserved polybasic region (PB3) present in both animals and fungi septins, and a Lys (K367) within its putative amphipathic helix (AH) that we demonstrate as important for lipid binding. PB3 deletion or mutation of this Lys (K367A) strongly impairs lipid interaction. Remarkably, we observe that the AH within a construct lacking the final 43 amino acid residues is insufficient for lipid binding. Furthermore, we investigate the homocomplex formed by <em>Sm</em>SEPT10 CTD in solution by cross-linking experiments, CD spectroscopy, SEC-MALS and SEC-SAXS. Taken together, our studies define the lipid-binding region in <em>Sm</em>SEPT10 and offer insights into the molecular basis of septin-membrane binding. This information is particularly relevant for less-studied non-human septins, such as <em>Sm</em>SEPT10.</p></div>","PeriodicalId":8831,"journal":{"name":"Biochimica et biophysica acta. Biomembranes","volume":null,"pages":null},"PeriodicalIF":2.8,"publicationDate":"2024-07-16","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"141695694","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":3,"RegionCategory":"生物学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

引用次数: 0

Pathological mutations in the phospholamban cytoplasmic region affect its topology and dynamics modulating the extent of SERCA inhibition 磷脂酰班细胞质区域的病理突变会影响其拓扑结构和动力学，从而调节 SERCA 的抑制程度。

IF 2.8 3区生物学

Biochimica et biophysica acta. Biomembranes Pub Date : 2024-07-08 DOI: 10.1016/j.bbamem.2024.184370

{"title":"Pathological mutations in the phospholamban cytoplasmic region affect its topology and dynamics modulating the extent of SERCA inhibition","authors":"","doi":"10.1016/j.bbamem.2024.184370","DOIUrl":"10.1016/j.bbamem.2024.184370","url":null,"abstract":"<div><p>Phospholamban (PLN) is a 52 amino acid regulin that allosterically modulates the activity of the sarco(endo)plasmic reticulum Ca<sup>2+</sup>-ATPase (SERCA) in the heart muscle. In its unphosphorylated form, PLN binds SERCA within its transmembrane (TM) domains, approximately 20 Å away from the Ca<sup>2+</sup> binding site, reducing SERCA's apparent Ca<sup>2+</sup> affinity (pK<sub>Ca</sub>) and decreasing cardiac contractility. During the enzymatic cycle, the inhibitory TM domain of PLN remains anchored to SERCA, whereas its cytoplasmic region transiently binds the ATPase's headpiece. Phosphorylation of PLN at Ser16 by protein kinase A increases the affinity of its cytoplasmic domain to SERCA, weakening the TM interactions with the ATPase, reversing its inhibitory function, and augmenting muscle contractility. How the structural changes caused by pathological mutations in the PLN cytoplasmic region are transmitted to its inhibitory TM domain is still unclear. Using solid-state NMR spectroscopy and activity assays, we analyzed the structural and functional effects of a series of mutations and their phosphorylated forms located in the PLN cytoplasmic region and linked to dilated cardiomyopathy. We found that these missense mutations affect the overall topology and dynamics of PLN and ultimately modulate its inhibitory potency. Also, the changes in the TM tilt angle and cytoplasmic dynamics of PLN caused by these mutations correlate well with the extent of SERCA inhibition. Our study unveils new molecular determinants for designing variants of PLN that outcompete endogenous PLN to regulate SERCA in a tunable manner.</p></div>","PeriodicalId":8831,"journal":{"name":"Biochimica et biophysica acta. Biomembranes","volume":null,"pages":null},"PeriodicalIF":2.8,"publicationDate":"2024-07-08","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"141578911","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":3,"RegionCategory":"生物学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

引用次数: 0

The cytoplasmic tail of myelin protein zero induces morphological changes in lipid membranes 髓鞘蛋白0的胞质部尾部可诱导脂膜发生形态变化。

IF 2.8 3区生物学

Biochimica et biophysica acta. Biomembranes Pub Date : 2024-07-04 DOI: 10.1016/j.bbamem.2024.184368

Oda C. Krokengen , Christine Touma , Anna Mularski , Aleksi Sutinen , Ryan Dunkel , Marie Ytterdal , Arne Raasakka , Haydyn D.T. Mertens , Adam Cohen Simonsen , Petri Kursula

{"title":"The cytoplasmic tail of myelin protein zero induces morphological changes in lipid membranes","authors":"Oda C. Krokengen , Christine Touma , Anna Mularski , Aleksi Sutinen , Ryan Dunkel , Marie Ytterdal , Arne Raasakka , Haydyn D.T. Mertens , Adam Cohen Simonsen , Petri Kursula","doi":"10.1016/j.bbamem.2024.184368","DOIUrl":"10.1016/j.bbamem.2024.184368","url":null,"abstract":"<div><p>The major myelin protein expressed by the peripheral nervous system Schwann cells is protein zero (P0), which represents 50% of the total protein content in myelin. This 30-kDa integral membrane protein consists of an immunoglobulin (Ig)-like domain, a transmembrane helix, and a 69-residue C-terminal cytoplasmic tail (P0ct). The basic residues in P0ct contribute to the tight packing of myelin lipid bilayers, and alterations in the tail affect how P0 functions as an adhesion molecule necessary for the stability of compact myelin. Several neurodegenerative neuropathies are related to P0, including the more common Charcot-Marie-Tooth disease (CMT) and Dejerine-Sottas syndrome (DSS) as well as rare cases of motor and sensory polyneuropathy. We found that high P0ct concentrations affected the membrane properties of bicelles and induced a lamellar-to-inverted hexagonal phase transition, which caused bicelles to fuse into long, protein-containing filament-like structures. These structures likely reflect the formation of semicrystalline lipid domains with potential relevance for myelination. Not only is P0ct important for stacking lipid membranes, but time-lapse fluorescence microscopy also shows that it might affect membrane properties during myelination. We further describe recombinant production and low-resolution structural characterization of full-length human P0. Our findings shed light on P0ct effects on membrane properties, and with the successful purification of full-length P0, we have new tools to study the role of P0 in myelin formation and maintenance <em>in vitro</em>.</p></div>","PeriodicalId":8831,"journal":{"name":"Biochimica et biophysica acta. Biomembranes","volume":null,"pages":null},"PeriodicalIF":2.8,"publicationDate":"2024-07-04","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://www.sciencedirect.com/science/article/pii/S0005273624000993/pdfft?md5=73f9ff16494baa69786ba4b3fc036813&pid=1-s2.0-S0005273624000993-main.pdf","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"141544479","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":3,"RegionCategory":"生物学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"OA","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

引用次数: 0

Distinct regions of its first intracellular loop contribute to the proper localization, transport activity and substrate-affinity adjustment of the main yeast K+ importer Trk1 其细胞内第一环的不同区域有助于主要酵母 K+ 导入器 Trk1 的正确定位、转运活性和底物亲和性调整。

IF 2.8 3区生物学

Biochimica et biophysica acta. Biomembranes Pub Date : 2024-07-03 DOI: 10.1016/j.bbamem.2024.184369

Klara Papouskova, Olga Zimmermannova, Hana Sychrova

{"title":"Distinct regions of its first intracellular loop contribute to the proper localization, transport activity and substrate-affinity adjustment of the main yeast K+ importer Trk1","authors":"Klara Papouskova, Olga Zimmermannova, Hana Sychrova","doi":"10.1016/j.bbamem.2024.184369","DOIUrl":"10.1016/j.bbamem.2024.184369","url":null,"abstract":"<div><p>Trk1 is the main K<sup>+</sup> importer of <em>Saccharomyces cerevisiae</em>. Its proper functioning enables yeast cells to grow in environments with micromolar amounts of K<sup>+</sup>. Although the structure of Trk1 has not been experimentally determined, the transporter is predicted to be composed of four MPM (transmembrane segment – pore loop – transmembrane segment) motifs which are connected by intracellular loops. Of those, in particular the first loop (IL1) is unique in its length; it forms more than half of the entire protein. The deletion of the majority of IL1 does not abolish the transport activity of Trk1. However IL1 is thought to be involved in the modulation of the transporter's functioning. In this work, we prepared a series of internally shortened versions of Trk1 that lacked various parts of IL1, and we studied their properties in <em>S. cerevisiae</em> cells without chromosomal copies of <em>TRK</em> genes. Using this approach, we were able to determine that both N- and C-border regions of IL1 are necessary for the proper localization of Trk1. Moreover, the N-border part of IL1 is also important for the functioning of Trk1, as its absence resulted in a decrease in the transporter's substrate affinity. In addition, in the internal part of IL1, we newly identified a stretch of amino-acid residues that are indispensable for retaining the transporter's maximum velocity, and another region whose deletion affected the ability of Trk1 to adjust its affinity in response to external levels of K<sup>+</sup>.</p></div>","PeriodicalId":8831,"journal":{"name":"Biochimica et biophysica acta. Biomembranes","volume":null,"pages":null},"PeriodicalIF":2.8,"publicationDate":"2024-07-03","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"141537455","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":3,"RegionCategory":"生物学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

引用次数: 0

The molecular determinants of calcium ATPase inhibition by curcuminoids 姜黄素抑制钙 ATP 酶的分子决定因素

IF 2.8 3区生物学

Biochimica et biophysica acta. Biomembranes Pub Date : 2024-07-03 DOI: 10.1016/j.bbamem.2024.184367

Stefan Paula, Sergiu Floruta, Karim Pajazetovic, Sydni Sobota, Dina Almahmodi

{"title":"The molecular determinants of calcium ATPase inhibition by curcuminoids","authors":"Stefan Paula, Sergiu Floruta, Karim Pajazetovic, Sydni Sobota, Dina Almahmodi","doi":"10.1016/j.bbamem.2024.184367","DOIUrl":"10.1016/j.bbamem.2024.184367","url":null,"abstract":"<div><p>The natural product curcumin and some of its analogs are known inhibitors of the transmembrane enzyme sarco/endoplasmic reticulum calcium ATPase (SERCA). Despite their widespread use, the curcuminoids' binding site in SERCA and their relevant interactions with the enzyme remain elusive. This lack of knowledge has prevented the development of curcuminoids into valuable experimental tools or into agents of therapeutic value. We used the crystal structures of SERCA in its E1 conformation in conjunction with computational tools such as docking and surface screens to determine the most likely curcumin binding site, along with key enzyme/inhibitor interactions. Additionally, we determined the inhibitory potencies and binding affinities for a small set of curcumin analogs. The predicted curcumin binding site is a narrow cleft in the transmembrane section of SERCA, close to the transmembrane/cytosol interface. In addition to pronounced complementarity in shape and hydrophobicity profiles between curcumin and the binding pocket, several hydrogen bonds were observed that were spread over the entire curcumin scaffold, involving residues on several transmembrane helices. Docking-predicted interactions were compatible with experimental observations for inhibitory potencies and binding affinities. Based on these findings, we propose an inhibition mechanism that assumes that the presence of a curcuminoid in the binding site arrests the catalytic cycle of SERCA by preventing it from converting from the E1 to the E2 conformation. This blockage of conformational change is accomplished by a combination of steric hinderance and hydrogen-bond-based cross-linking of transmembrane helices that require flexibility throughout the catalytic cycle.</p></div>","PeriodicalId":8831,"journal":{"name":"Biochimica et biophysica acta. Biomembranes","volume":null,"pages":null},"PeriodicalIF":2.8,"publicationDate":"2024-07-03","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"141537456","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":3,"RegionCategory":"生物学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

引用次数: 0

Proposed dual membrane contact with full-length Osh4 建议与全长 Osh4 进行双膜接触。

IF 2.8 3区生物学

Biochimica et biophysica acta. Biomembranes Pub Date : 2024-07-01 DOI: 10.1016/j.bbamem.2024.184365

Sharmistha Karmakar , Jeffery B. Klauda

{"title":"Proposed dual membrane contact with full-length Osh4","authors":"Sharmistha Karmakar , Jeffery B. Klauda","doi":"10.1016/j.bbamem.2024.184365","DOIUrl":"10.1016/j.bbamem.2024.184365","url":null,"abstract":"<div><p>Membrane contacts sites (MCSs) play important roles in lipid trafficking across cellular compartments and maintain the widespread structural diversity of organelles. We have utilized microsecond long all-atom (AA) molecular dynamics (MD) simulations and enhanced sampling techniques to unravel the MCS structure targeting by yeast oxysterol binding protein (Osh4) in an environment that mimics the interface of membranes with an increased proportion of anionic lipids using CHARMM36m forcefield with additional CUFIX parameters for lipid-protein electrostatic interactions. In a dual-membrane environment, unbiased MD simulations show that Osh4 briefly interacts with both membranes, before aligning itself with a single membrane, adopting a β-crease-bound conformation similar to observations in a single-membrane scenario. Targeted molecular dynamics simulations followed by microsecond-long AA MD simulations have revealed a distinctive dual-membrane bound state of Osh4 at MCS, wherein the protein interacts with the lower membrane via the β-crease surface, featuring its PHE-239 residue positioned below the phosphate plane of membrane, while concurrently establishing contact with the opposite membrane through the extended α6-α7 region. Osh4 maintains these dual membrane contacts simultaneously over the course of microsecond-long MD simulations. Moreover, binding energy calculations highlighted the essential roles played by the phenylalanine loop and the α6 helix in dynamically stabilizing dual-membrane bound state of Osh4 at MCS. Our computational findings were corroborated through frequency of contact analysis, showcasing excellent agreement with past experimental cross-linking data. Our computational study reveals a dual-membrane bound conformation of Osh4, providing insights into protein-membrane interactions at membrane contact sites and their relevance to lipid transfer processes.</p></div>","PeriodicalId":8831,"journal":{"name":"Biochimica et biophysica acta. Biomembranes","volume":null,"pages":null},"PeriodicalIF":2.8,"publicationDate":"2024-07-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"141497007","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":3,"RegionCategory":"生物学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

引用次数: 0

Mode of molecular interaction of triterpenoid saponin ginsenoside Rh2 with membrane lipids in liquid-disordered phases 三萜类皂苷人参皂苷 Rh2 与膜脂在液态有序相中的分子相互作用模式。

IF 2.8 3区生物学

Biochimica et biophysica acta. Biomembranes Pub Date : 2024-07-01 DOI: 10.1016/j.bbamem.2024.184366

Darcy Garza-Miyazato , Shinya Hanashima , Yuichi Umegawa , Michio Murata , Masanao Kinoshita , Nobuaki Matsumori , Peter Greimel

{"title":"Mode of molecular interaction of triterpenoid saponin ginsenoside Rh2 with membrane lipids in liquid-disordered phases","authors":"Darcy Garza-Miyazato , Shinya Hanashima , Yuichi Umegawa , Michio Murata , Masanao Kinoshita , Nobuaki Matsumori , Peter Greimel","doi":"10.1016/j.bbamem.2024.184366","DOIUrl":"10.1016/j.bbamem.2024.184366","url":null,"abstract":"<div><p>Ginsenoside Rh2 (Rh2) is a ginseng saponin comprising a triterpene core and one unit of glucose and has attracted much attention due to its diverse biological activities. In the present study, we used small-angle X-ray diffraction, solid-state NMR, fluorescence microscopy, and MD simulations to investigate the molecular interaction of Rh2 with membrane lipids in the liquid-disordered (Ld) phase mainly composed of palmitoyloleoylphosphatidylcholine compared with those in liquid-ordered (Lo) phase mainly composed of sphingomyelin and cholesterol. The electron density profiles determined by X-ray diffraction patterns indicated that Rh2 tends to be present in the shallow interior of the bilayer in the Ld phase, while Rh2 accumulation was significantly smaller in the Lo phase. Order parameters at intermediate depths in the bilayer leaflet obtained from <sup>2</sup>H NMR spectra and MD simulations indicated that Rh2 reduces the order of the acyl chains of lipids in the Ld phase. The dihydroxy group and glucose moiety at both ends of the hydrophobic triterpene core of Rh2 cause tilting of the molecular axis relative to the membrane normal, which may enhance membrane permeability by loosening the packing of lipid acyl chains. These features of Rh2 are distinct from steroidal saponins such as digitonin and dioscin, which exert strong membrane-disrupting activity.</p></div>","PeriodicalId":8831,"journal":{"name":"Biochimica et biophysica acta. Biomembranes","volume":null,"pages":null},"PeriodicalIF":2.8,"publicationDate":"2024-07-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"141497006","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":3,"RegionCategory":"生物学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

引用次数: 0

Identification of subcomplexes and protein-protein interactions in the DNA transporter of Thermus thermophilus HB27 鉴定嗜热菌 HB27 DNA 转运体中的亚复合物和蛋白质之间的相互作用。

IF 2.8 3区生物学

Biochimica et biophysica acta. Biomembranes Pub Date : 2024-06-22 DOI: 10.1016/j.bbamem.2024.184363

Deniz Yaman, Beate Averhoff

{"title":"Identification of subcomplexes and protein-protein interactions in the DNA transporter of Thermus thermophilus HB27","authors":"Deniz Yaman, Beate Averhoff","doi":"10.1016/j.bbamem.2024.184363","DOIUrl":"10.1016/j.bbamem.2024.184363","url":null,"abstract":"<div><p>The natural transformation system of the thermophilic bacterium <em>Thermus thermophilus</em> comprises at least 16 competence proteins. Recently we found that the outer membrane (OM) competence protein PilW interacts with the secretin channel, which guides type IV pili (T4P) and potential DNA transporter pseudopili through the OM. Here we have used biochemical techniques to study the interactions of cytoplasmic, inner membrane (IM) and OM components of the DNA transporter in <em>T. thermophilus</em>. We report that PilW is part of a heteropolymeric complex comprising of the cytoplasmic PilM protein, IM proteins PilN, PilO, PilC and the secretin PilQ. Co-purification studies revealed that PilO directly interacts with PilW. <em>In vitro</em> affinity co-purification studies using His-tagged PilC led to the detection of PilC-, PilW-, PilN- and PilO-containing complexes. PilO was identified as direct interaction partner of the polytopic IM protein PilC. PilC was also found to directly interact with the cytoplasmic T4P disassembly ATPase PilT1 thereby triggering PilT1 ATPase activity. This, together with the detection of heteropolymeric PilC complexes which contain PilT1 and the pilins PilA2, PilA4 and PilA5 is in line with the hypothesis that PilC connects the depolymerization ATPase to the base of the pili possibly allowing energy transduction for disassembly of the pilins.</p></div>","PeriodicalId":8831,"journal":{"name":"Biochimica et biophysica acta. Biomembranes","volume":null,"pages":null},"PeriodicalIF":2.8,"publicationDate":"2024-06-22","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://www.sciencedirect.com/science/article/pii/S0005273624000944/pdfft?md5=68b6d381a162db3111f046e94622cd9e&pid=1-s2.0-S0005273624000944-main.pdf","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"141442096","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":3,"RegionCategory":"生物学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"OA","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

引用次数: 0

Effect of colloidal magnetite (Fe3O4) nanoparticles on the electrical characteristics of the azolectin bilayer in a static inhomogeneous magnetic field 胶体磁铁矿（Fe3O4）纳米粒子对静态非均相磁场中偶氮蛋白双分子层电气特性的影响。

IF 2.8 3区生物学

Biochimica et biophysica acta. Biomembranes Pub Date : 2024-06-20 DOI: 10.1016/j.bbamem.2024.184352

A.A. Anosov , E.Yu. Smirnova , V.I. Sukhova , E.D. Borisova , R.B. Morgunov , I.V. Taranov , I.V. Grigoryan , V.A. Cherepenin , G.B. Khomutov

{"title":"Effect of colloidal magnetite (Fe3O4) nanoparticles on the electrical characteristics of the azolectin bilayer in a static inhomogeneous magnetic field","authors":"A.A. Anosov , E.Yu. Smirnova , V.I. Sukhova , E.D. Borisova , R.B. Morgunov , I.V. Taranov , I.V. Grigoryan , V.A. Cherepenin , G.B. Khomutov","doi":"10.1016/j.bbamem.2024.184352","DOIUrl":"10.1016/j.bbamem.2024.184352","url":null,"abstract":"<div><p>This work is devoted to the study of the combined effects of applied magnetic field and MNPs on the electrical characteristics of bilayer lipid membranes. We present results of the study of electrical parameters of azolectin membranes in a static inhomogeneous magnetic field at the one-sided addition of positively charged quasi-spherical superparamagnetic magnetite nanoparticles with a diameter of about 4 nm. The magnet was located at different distances from the membrane, and the magnetic field attracted the nanoparticles to the membrane surface with different strengths. We observed three pronounced effects that depended on the external magnetic field. Firstly, after addition of nanoparticles in a magnetic field, the conductance of the membranes increased. A smooth increase in conductance was accompanied in some cases by the appearance of current jumps, which can be associated with the formation of through pores with a radius of no more than 1 nm. The conductance increased with increasing magnetic field gradient. Secondly, at zero command voltage, a negative current through the membrane was observed. Although our experiments did not allow us to unambiguously determine which particles create this current, we believe that this current is associated with the penetration of particles through the membrane. This effect intensified with increasing magnetic field gradient. Thirdly, we observed a sharp change in the nonlinear dependence of capacitance on voltage associated both with the change in the surface potential of the azolectin membrane and with the effect of MNP binding to the membrane surface on the apparent membrane capacitance.</p></div>","PeriodicalId":8831,"journal":{"name":"Biochimica et biophysica acta. Biomembranes","volume":null,"pages":null},"PeriodicalIF":2.8,"publicationDate":"2024-06-20","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"141440163","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":3,"RegionCategory":"生物学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

引用次数: 0

Computational analysis of the simultaneous application of ultrasound and electric fields in a lipid bilayer 在脂质双分子层中同时应用超声波和电场的计算分析。

IF 2.8 3区生物学

Biochimica et biophysica acta. Biomembranes Pub Date : 2024-06-18 DOI: 10.1016/j.bbamem.2024.184364

Wagner Augusto Müller, Júlia Ribeiro Sarkis, Ligia Damasceno Ferreira Marczak, André Rodrigues Muniz

{"title":"Computational analysis of the simultaneous application of ultrasound and electric fields in a lipid bilayer","authors":"Wagner Augusto Müller, Júlia Ribeiro Sarkis, Ligia Damasceno Ferreira Marczak, André Rodrigues Muniz","doi":"10.1016/j.bbamem.2024.184364","DOIUrl":"10.1016/j.bbamem.2024.184364","url":null,"abstract":"<div><p>The combined application of electric fields and ultrasonic waves has shown promise in controlling cell membrane permeability, potentially resulting in synergistic effects that can be explored in the biotechnology industry. However, further clarification on how these processes interact is still needed. The objective of the present study was to investigate the atomic-scale effects of these processes on a DPPC lipid bilayer using molecular dynamics simulations. For higher electric fields, capable of independently forming pores, the application of an ultrasonic wave in the absence of cavitation yielded no additional effects on pore formation. However, for lower electric fields, the reduction in bilayer thickness induced by the shock wave catalyzed the electroporation process, effectively shortening the mean path that water molecules must traverse to form pores. When cavitation was considered, synergistic effects were evident only if the wave alone was able to generate pores through the formation of a water nanojet. In these cases, sonoporation acted as a mean to focus the electroporation effects on the initial pore formed by the nanojet. This study contributes to a better understanding of the synergy between electric fields and ultrasonic waves and to an optimal selection of processing parameters in practical applications of these processes.</p></div>","PeriodicalId":8831,"journal":{"name":"Biochimica et biophysica acta. Biomembranes","volume":null,"pages":null},"PeriodicalIF":2.8,"publicationDate":"2024-06-18","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"141431265","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":3,"RegionCategory":"生物学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

引用次数: 0