Biochimica et biophysica acta. Biomembranes最新文献_第5页

Influence of archaeal lipids isolated from Aeropyrum pernix K1 on physicochemical properties of sphingomyelin-cholesterol liposomes 从 Aeropyrum pernix K1 中分离出的古菌脂质对鞘磷脂-胆固醇脂质体理化性质的影响。

IF 2.8 3区生物学

Biochimica et biophysica acta. Biomembranes Pub Date : 2024-07-23 DOI: 10.1016/j.bbamem.2024.184374

Jan Kejžar , Polona Mrak , Ilja Gasan Osojnik Črnivec , Nataša Poklar Ulrih

{"title":"Influence of archaeal lipids isolated from Aeropyrum pernix K1 on physicochemical properties of sphingomyelin-cholesterol liposomes","authors":"Jan Kejžar , Polona Mrak , Ilja Gasan Osojnik Črnivec , Nataša Poklar Ulrih","doi":"10.1016/j.bbamem.2024.184374","DOIUrl":"10.1016/j.bbamem.2024.184374","url":null,"abstract":"<div><p>We investigated the influence of archaeal lipids (C<sub>25,25</sub>) isolated from thermophilic archaeon <em>Aeropyrum pernix</em> K1 on physicochemical properties of liposomes comprised of egg sphingomyelin (SM) and cholesterol (CH) using fluorescence emission anisotropy, calcein release studies, dynamic light scattering, transmission electron microscopy and phase analysis light scattering. The 2 mol% addition of archaeal lipids enabled formation of small unilamellar vesicles by sonication while also having significant effect on reducing mean size, polydispersity index and zeta potential of C<sub>25,25</sub>/SM/CH vesicles. Increasing the ratio of C<sub>25,25</sub> lipids in mixture of C<sub>25,25</sub>/SM/CH decreased lipid ordering parameter in dose dependent manner at different temperatures. We also demonstrated that adding 15 mol% C<sub>25,25</sub> to SM/CH mixture will cause it to notably interact with fetal bovine serum which could make them a viable alternative adjuvant to synthetic ether-linked lipids in development of advanced liposomal vaccine delivery systems. The prospect of combining the proven strengths of SM/CH mixtures with the unique properties of C<sub>25,25</sub> opens exciting possibilities for advancing drug delivery technologies, promising to yield formulations that are both highly effective and adaptable to a range of therapeutic applications.</p></div>","PeriodicalId":8831,"journal":{"name":"Biochimica et biophysica acta. Biomembranes","volume":"1866 7","pages":"Article 184374"},"PeriodicalIF":2.8,"publicationDate":"2024-07-23","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://www.sciencedirect.com/science/article/pii/S0005273624001056/pdfft?md5=afd73738d180040195ca0dedcd675148&pid=1-s2.0-S0005273624001056-main.pdf","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"141756814","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

Lipid composition affects the thermal stability of cytochrome P450 3A4 in nanodiscs 脂质成分影响纳米盘中细胞色素 P450 3A4 的热稳定性。

IF 2.8 3区生物学

Biochimica et biophysica acta. Biomembranes Pub Date : 2024-07-22 DOI: 10.1016/j.bbamem.2024.184372

Tim G.J. Knetsch, Marcellus Ubbink

{"title":"Lipid composition affects the thermal stability of cytochrome P450 3A4 in nanodiscs","authors":"Tim G.J. Knetsch, Marcellus Ubbink","doi":"10.1016/j.bbamem.2024.184372","DOIUrl":"10.1016/j.bbamem.2024.184372","url":null,"abstract":"<div><p>Nanodiscs (NDs), self-assembled lipid bilayers encircled by membrane scaffold proteins (MSPs), offer a versatile platform for the reconstitution of membrane proteins for structural and biochemical investigations. Saturated, isoprenoid lipids are commonly found in thermophiles and have been associated with thermotolerance. To test whether these lipids confer additional stability on ND-incorporated membrane proteins, this study focuses on the thermal stability of human cytochrome P450 3A4 (CYP3A4) inside NDs composed of different phosphocholine lipids: 1-palmitoyl-2-oleoyl-sn-glycero-3-phosphocholine (POPC), 1,2-dimyristoyl-sn-glycero-3-phosphocholine (DMPC), and 1,2-diphytanoyl-sn-glycero-3-phosphocholine (DPhPC). NDs were characterized using size-exclusion chromatography coupled with multi-angle light scattering (SEC-MALS) and densitometric SDS-PAGE. CYP3A4-DPhPC-NDs were found to comprise three MSP copies instead of the canonical dimer, as reported before for the empty NDs. Rapid, thermally induced unfolding of CYP3A4 inside NDs measured using circular dichroism and differential scanning fluorimetry (nanoDSF) revealed that the CYP3A4 melting temperature was dependent on ND composition. In POPC and DMPC-CYP3A4-NDs the melting temperature was comparable to CYP3A4 without NDs (59 °C). CYP3A4 in DPhPC-NDs showed an increase in melting temperature of 4 °C. Decline in CYP3A4 integrity as well as ND aggregation and disintegration occur at similar rates for all membrane types when subjected to exposure at 37 °C for several hours. The POPC and DMPC- CYP3A4-NDs show significant lipid loss over time, which is not observed for DPhPC-NDs. The results demonstrate that thermally induced denaturation of protein-NDs is a complex, multifaceted process, which is not represented well by rapid thermal unfolding experiments.</p></div>","PeriodicalId":8831,"journal":{"name":"Biochimica et biophysica acta. Biomembranes","volume":"1866 7","pages":"Article 184372"},"PeriodicalIF":2.8,"publicationDate":"2024-07-22","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://www.sciencedirect.com/science/article/pii/S0005273624001032/pdfft?md5=1cb18708a6c65e795da8bb046d83b80f&pid=1-s2.0-S0005273624001032-main.pdf","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"141756815","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

The impact of transmembrane peptides on lipid bilayer structure and mechanics: A study of the transmembrane domain of the influenza A virus M2 protein 跨膜肽对脂质双分子层结构和力学的影响：对甲型流感病毒 M2 蛋白跨膜结构域的研究。

IF 2.8 3区生物学

Biochimica et biophysica acta. Biomembranes Pub Date : 2024-07-22 DOI: 10.1016/j.bbamem.2024.184373

Yasith Indigahawela Gamage, Yasinthara Wadumesthri, Humberto Rodríguez Gutiérrez, Dmitri V. Voronine, Jianjun Pan

{"title":"The impact of transmembrane peptides on lipid bilayer structure and mechanics: A study of the transmembrane domain of the influenza A virus M2 protein","authors":"Yasith Indigahawela Gamage, Yasinthara Wadumesthri, Humberto Rodríguez Gutiérrez, Dmitri V. Voronine, Jianjun Pan","doi":"10.1016/j.bbamem.2024.184373","DOIUrl":"10.1016/j.bbamem.2024.184373","url":null,"abstract":"<div><p>Transmembrane peptides play important roles in many biological processes by interacting with lipid membranes. This study investigates how the transmembrane domain of the influenza A virus M2 protein, M2TM, affects the structure and mechanics of model lipid bilayers. Atomic force microscopy (AFM) imaging revealed small decreases in bilayer thickness with increasing peptide concentrations. AFM-based force spectroscopy experiments complemented by theoretical model analysis demonstrated significant decreases in bilayer's Young's modulus (E) and lateral area compressibility modulus (K<sub>A</sub>). This suggests that M2TM disrupts the cohesive interactions between neighboring lipid molecules, leading to a decrease in both the bilayer's resistance to indentation (E) and its ability to resist lateral compression/expansion (K<sub>A</sub>). The large decreases in bilayer elastic parameters (i.e., E and K<sub>A</sub>) contrast with small changes in bilayer thickness, implying that bilayer mechanics are not solely dictated by bilayer thickness in the presence of transmembrane peptides. The observed significant reduction in bilayer mechanical properties suggests a softening effect on the bilayer, potentially facilitating membrane curvature generation, a crucial step for M2-mediated viral budding. In parallel, our Raman spectroscopy revealed small but statistically significant changes in hydrocarbon chain vibrational dynamics, indicative of minor disordering in lipid chain conformation. Our findings provide useful insights into the complex interplay between transmembrane peptides and lipid bilayers, highlighting the significance of peptide-lipid interactions in modulating membrane structure, mechanics, and molecular dynamics.</p></div>","PeriodicalId":8831,"journal":{"name":"Biochimica et biophysica acta. Biomembranes","volume":"1866 7","pages":"Article 184373"},"PeriodicalIF":2.8,"publicationDate":"2024-07-22","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"141756896","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

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":"1866 7","pages":"Article 184371"},"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":"1866 7","pages":"Article 184370"},"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":"1866 7","pages":"Article 184368"},"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":"1866 7","pages":"Article 184369"},"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":"1866 7","pages":"Article 184367"},"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":"1866 7","pages":"Article 184365"},"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":"1866 7","pages":"Article 184366"},"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