Biochimica et biophysica acta. Biomembranes最新文献

Growth of Staphylococcus aureus in the presence of oleic acid shifts the glycolipid fatty acid profile and increases resistance to antimicrobial peptides. 金黄色葡萄球菌在油酸存在下的生长会改变糖脂脂肪酸谱，并增加对抗菌肽的耐药性。

IF 2.8 3区生物学

Biochimica et biophysica acta. Biomembranes Pub Date : 2024-11-03 DOI: 10.1016/j.bbamem.2024.184395

Djuro Raskovic, Gloria Alvarado, Kelly M Hines, Libin Xu, Craig Gatto, Brian J Wilkinson, Antje Pokorny

{"title":"Growth of Staphylococcus aureus in the presence of oleic acid shifts the glycolipid fatty acid profile and increases resistance to antimicrobial peptides.","authors":"Djuro Raskovic, Gloria Alvarado, Kelly M Hines, Libin Xu, Craig Gatto, Brian J Wilkinson, Antje Pokorny","doi":"10.1016/j.bbamem.2024.184395","DOIUrl":"10.1016/j.bbamem.2024.184395","url":null,"abstract":"<p><p>Staphylococcus aureus readily adapts to various environments and quickly develops antibiotic resistance, which has led to an increase in multidrug-resistant infections. Hence, S. aureus presents a significant global health issue and its adaptations to the host environment are crucial for understanding pathogenesis and antibiotic susceptibility. When S. aureus is grown conventionally, its membrane lipids contain a mix of branched-chain and straight-chain saturated fatty acids. However, when unsaturated fatty acids are present in the growth medium, they become a major part of the total fatty acid composition. This study explores the biophysical effects of incorporating straight-chain unsaturated fatty acids into S. aureus membrane lipids. Membrane preparations from cultures supplemented with oleic acid showed more complex differential scanning calorimetry scans than those grown in tryptic soy broth alone. When grown in the presence of oleic acid, the cultures exhibited a transition significantly above the growth temperature, attributed to the presence of glycolipids with long-chain fatty acids causing acyl chain packing frustration within the bilayer. Functional aspects of the membrane were assessed by studying the kinetics of dye release from unilamellar vesicles induced by the antimicrobial peptide mastoparan X. Dye release was slower from liposomes prepared from cells grown in oleic acid-supplemented cultures, suggesting that changes in membrane lipid composition and biophysics protect the cell membrane against peptide-induced lysis. These findings underscore the intricate relationship between the growth environment, membrane lipid composition, and the physical properties of the bacterial membrane, which should be considered when developing new strategies against S. aureus infections.</p>","PeriodicalId":8831,"journal":{"name":"Biochimica et biophysica acta. Biomembranes","volume":null,"pages":null},"PeriodicalIF":2.8,"publicationDate":"2024-11-03","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142582032","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

Voltage- and Ca2+-inducible PLC activity for analyzing PI(4,5)P2 sensitivity of ion channels in Xenopus oocytes 电压和 Ca2+ 诱导的 PLC 活性，用于分析爪蟾卵母细胞中离子通道对 PI(4,5)P2 的敏感性。

IF 2.8 3区生物学

Biochimica et biophysica acta. Biomembranes Pub Date : 2024-10-30 DOI: 10.1016/j.bbamem.2024.184396

Takafumi Kawai , Natsuki Mizutani , Yasushi Okamura

{"title":"Voltage- and Ca2+-inducible PLC activity for analyzing PI(4,5)P2 sensitivity of ion channels in Xenopus oocytes","authors":"Takafumi Kawai , Natsuki Mizutani , Yasushi Okamura","doi":"10.1016/j.bbamem.2024.184396","DOIUrl":"10.1016/j.bbamem.2024.184396","url":null,"abstract":"<div><div>Phosphatidylinositol 4,5-bisphosphate (PIP<sub>2</sub>) is a key membrane lipid regulating various ion channel activities. Currently, several molecular tools are used to modulate PIP<sub>2</sub> levels, each of which has distinct advantages and drawbacks. In this study, we proposed a novel methodology using heterologous <em>Xenopus</em> oocytes to precisely manipulate PIP<sub>2</sub> levels using phospholipase C (PLC)-ζ, which hydrolyzes PIP<sub>2</sub>. <em>Xenopus</em> oocytes injected with PLCζ exhibited notable hyperpolarization-induced Ca<sup>2+</sup> influx driven by the increased driving force of Ca<sup>2+</sup>. High Ca<sup>2+</sup> sensitivity of PLCζ facilitated hyperpolarization-induced PLC activity in <em>Xenopus</em> oocytes that was voltage- and Ca<sup>2+</sup>-dependent. This study demonstrated the regulatory capacity of PLCζ in modulating PIP<sub>2</sub>-sensitive ion channels, such as the KCNQ2/3 and GIRK channels, in a voltage- and Ca<sup>2+</sup>-dependent manner. Moreover, activation pathway of PLCζ only requires a two-electrode voltage clamp setup, making it a convenient molecular tool to manipulate PIP<sub>2</sub> levels in combination with a voltage-sensing phosphatase (VSP). PLCζ has distinct characteristics and advantages compared to VSP: (1) Hyperpolarization, but not depolarization, reduced the PIP<sub>2</sub> levels, (2) PIP<sub>2</sub> levels were decreased without any increase in phosphatidylinositol 4-monophosphate (PIP) levels, and (3) PIP<sub>2</sub> levels were reduced by Ca<sup>2+</sup> administration. Therefore, PLCζ effectively supports understanding how PIP<sub>2</sub> regulates ion channels, alongside VSP. Overall, this study highlights the unique characteristics of PLCζ and its distinct advantages in analyzing ion channel regulation by PIP<sub>2</sub> and the PLC pathway in <em>Xenopus</em> oocytes.</div></div>","PeriodicalId":8831,"journal":{"name":"Biochimica et biophysica acta. Biomembranes","volume":null,"pages":null},"PeriodicalIF":2.8,"publicationDate":"2024-10-30","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142557053","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

Tuning expression of GPCRs for the secretory pathway in the baculovirus-insect cell expression system. 在杆状病毒-昆虫细胞表达系统中调节分泌途径 GPCR 的表达。

IF 2.8 3区生物学

Biochimica et biophysica acta. Biomembranes Pub Date : 2024-10-27 DOI: 10.1016/j.bbamem.2024.184397

Jakob Aastrup Jørgensen

{"title":"Tuning expression of GPCRs for the secretory pathway in the baculovirus-insect cell expression system.","authors":"Jakob Aastrup Jørgensen","doi":"10.1016/j.bbamem.2024.184397","DOIUrl":"https://doi.org/10.1016/j.bbamem.2024.184397","url":null,"abstract":"<p><p>The overexpression of G-protein-coupled receptors (GPCRs) remains one of the biggest hurdles for structural studies of these proteins. To date, the most usually applied system for this task is the insect cell/baculovirus expression system. A drawback of this system, however, is the accumulation of protein that is resistant to solubilization with the commonly used mild detergent DoDecylMaltoside (DDM). In addition, poor surface expression is often observed. In this study, it is shown how an earlier AcMNPV 39K promoter, can express receptors that are found primarily on the cell membrane, as revealed by confocal microscopy, and the protein can be solubilized to a higher degree by DDM in a less aggregation-prone form, as monitored by fluorescence size-exclusion chromatography. In addition, a strong effect on the yield was observed when the AcMNPV gp67 signal sequence was used. The documentation of the 39K promoter as an improvement over the frequently used polyhedrin promoter, along with the effect of the gp67 signal sequence are important steps toward ultimately improving the expression in terms of total functional yield, while also shedding light on the nature of the process of overproduction of membrane proteins, in particular, GPCRs.</p>","PeriodicalId":8831,"journal":{"name":"Biochimica et biophysica acta. Biomembranes","volume":null,"pages":null},"PeriodicalIF":2.8,"publicationDate":"2024-10-27","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142543407","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

Lipid bilayer permeabilities and antibiotic effects of tetramethylguanidinium and choline fatty acid ionic liquids 四甲基胍和胆碱脂肪酸离子液体的脂质双分子层渗透性和抗生素效应。

IF 2.8 3区生物学

Biochimica et biophysica acta. Biomembranes Pub Date : 2024-10-22 DOI: 10.1016/j.bbamem.2024.184393

Achismita Dutta , Brandon Burrell , Esha Prajapati , Sierra Cottle , Hailey Y. Maurer , Matthew J. Urban , Samuel R. Pennock , Arwa M. Muhamed , Janiyah Harris , Yesenia Flores , Lauren Staman , Benjamin R. Carone , Gregory A. Caputo , Timothy D. Vaden

{"title":"Lipid bilayer permeabilities and antibiotic effects of tetramethylguanidinium and choline fatty acid ionic liquids","authors":"Achismita Dutta , Brandon Burrell , Esha Prajapati , Sierra Cottle , Hailey Y. Maurer , Matthew J. Urban , Samuel R. Pennock , Arwa M. Muhamed , Janiyah Harris , Yesenia Flores , Lauren Staman , Benjamin R. Carone , Gregory A. Caputo , Timothy D. Vaden","doi":"10.1016/j.bbamem.2024.184393","DOIUrl":"10.1016/j.bbamem.2024.184393","url":null,"abstract":"<div><div>Ionic liquids (ILs) have been studied as potential components in antibiotic formulations based on their abilities to permeabilize and penetrate lipid bilayer, which correlate with their antibacterial effects. Fatty acid-based ILs (FAILs), in which the anion is a long-chain fatty acid, can permeabilize lipid membranes and have been used in biomedical applications since they have low human cell cytotoxicity. In this work we investigated the abilities of several different FAILs to permeabilize lipid bilayers and how that permeabilization correlates with antibacterial activity, cell membrane permeability, and cytotoxicity. The FAILs consisted of the cations tetramethylguanidinium (TMG) or choline combined with octanoate or decanoate. These FAILs were tested on model bilayer vesicles with three different lipid compositions for membrane permeabilization using a leakage assay. They were then tested for antibiotic and membrane permeabilization on bacterial and mammalian cells. The results show that while the octanoate-based FAILs do not form micelles and have low activities on vesicles and biological cells, the decanoate-based FAILs can permeabilize bilayers and have biological activities that correlate with the model vesicle results. The ILs with both cation and fatty-acid anion have strong activities while the decanoate alone has only minimal permeabilization and antibiotic activity. Membrane permeabilization occurs at FAIL concentrations below their CMC values which suggests that their mechanism of action may not involve micelle formation.</div></div>","PeriodicalId":8831,"journal":{"name":"Biochimica et biophysica acta. Biomembranes","volume":null,"pages":null},"PeriodicalIF":2.8,"publicationDate":"2024-10-22","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142493945","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

TNF receptors: Structure-function relationships and therapeutic targeting strategies TNF 受体：结构-功能关系和靶向治疗策略

IF 2.8 3区生物学

Biochimica et biophysica acta. Biomembranes Pub Date : 2024-10-22 DOI: 10.1016/j.bbamem.2024.184394

Chih Hung Lo

引用次数: 0

Conformational heterogeneity and structural features for function of the prototype viroporin influenza AM2 原型病毒蛋白流感 AM2 功能的构象异质性和结构特征。

IF 2.8 3区生物学

Biochimica et biophysica acta. Biomembranes Pub Date : 2024-10-17 DOI: 10.1016/j.bbamem.2024.184387

Kyriakos Georgiou, Antonios Kolocouris

{"title":"Conformational heterogeneity and structural features for function of the prototype viroporin influenza AM2","authors":"Kyriakos Georgiou, Antonios Kolocouris","doi":"10.1016/j.bbamem.2024.184387","DOIUrl":"10.1016/j.bbamem.2024.184387","url":null,"abstract":"<div><div>The 97-residue influenza A matrix 2 (ΑM2) protein, a prototype for viroporins, transports protons through water molecules and His37. We discuss structural biology and molecular biophysics experiments and some functional assays that have transformed over 40 years our understanding of the structure and function of AM2. The structural studies on ΑM2 have been performed with different conditions (pH, temperature, lipid, constructs) and using various protein constructs, e.g., AM2 transmembrane (AM2TM) domain, AM2 conductance domain (AM2CD), ectodomain-containing or ectodomain-truncated, AM2 full length (AM2FL) and aimed to describe the different conformations and structural details that are necessary for the stability and function of AM2. However, the conclusions from these experiments appeared sometimes ambiguous and caused exciting debates. This was not due to inaccurate measurements, but instead because of the different membrane mimetic environment used, e.g., detergent, micelles or phospholipid bilayer, the method (e.g., X-ray crystallography, solid state NMR, solution NMR, native mass spectrometry), the used protein construct (e.g., AM2TM or AM2CD), or the amino acids residues to follow observables (e.g., NMR chemical shifts). We present these results according to the different used biophysical methods, the research groups and often by keeping a chronological order for presenting the progress in the research. We discuss ideas for additional research on structural details of AM2 and how the present findings can be useful to explore new routes of influenza A inhibition. The AM2 research can provide inspiration to study other viroporins as drug targets.</div></div>","PeriodicalId":8831,"journal":{"name":"Biochimica et biophysica acta. Biomembranes","volume":null,"pages":null},"PeriodicalIF":2.8,"publicationDate":"2024-10-17","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142457073","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

Polymer nanodiscs support the functional extraction of an artificial transmembrane cytochrome 聚合物纳米盘支持人工跨膜细胞色素的功能提取

IF 2.8 3区生物学

Biochimica et biophysica acta. Biomembranes Pub Date : 2024-10-15 DOI: 10.1016/j.bbamem.2024.184392

Benjamin J. Hardy, Holly C. Ford, May Rudin, J.L. Ross Anderson, Paul Curnow

引用次数: 0

A comparison of lipid diffusive dynamics in monolayers and bilayers in the context of interleaflet coupling 在小叶间耦合的背景下比较单层和双层中的脂质扩散动力学。

IF 2.8 3区生物学

Biochimica et biophysica acta. Biomembranes Pub Date : 2024-10-12 DOI: 10.1016/j.bbamem.2024.184388

Titas Mandal , Nadine Brandt , Carmelo Tempra , Matti Javanainen , Balázs Fábián , Salvatore Chiantia

{"title":"A comparison of lipid diffusive dynamics in monolayers and bilayers in the context of interleaflet coupling","authors":"Titas Mandal , Nadine Brandt , Carmelo Tempra , Matti Javanainen , Balázs Fábián , Salvatore Chiantia","doi":"10.1016/j.bbamem.2024.184388","DOIUrl":"10.1016/j.bbamem.2024.184388","url":null,"abstract":"<div><div>Cellular membranes are composed of lipids typically organized in a double-leaflet structure. Interactions between these two leaflets – often referred to as interleaflet coupling – play a crucial role in various cellular processes. Despite extensive study, the mechanisms governing such interactions remain incompletely understood. Here, we investigate the effects of interleaflet coupling from a specific point of view, i.e. by comparing diffusive dynamics in bilayers and monolayers, focusing on potential lipid-specific interactions between opposing leaflets. Through quantitative fluorescence microscopy techniques, we characterize lipid diffusion and mean molecular area in monolayers and bilayers composed of different lipids. Our results suggest that the observed decrease in bilayer lipid diffusion compared to monolayers depends on lipid identity. Furthermore, our analysis suggests that lipid acyl chain structure and spatial configuration at the bilayer may strongly influence interleaflet interactions and dynamics in bilayers. These findings provide insights into the role of lipid structure in mediating interleaflet coupling and underscore the need for further experimental investigations to elucidate the underlying mechanisms.</div></div>","PeriodicalId":8831,"journal":{"name":"Biochimica et biophysica acta. Biomembranes","volume":null,"pages":null},"PeriodicalIF":2.8,"publicationDate":"2024-10-12","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142457072","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

Evidence for phospholipid self-organisation in concentrated ammonia-water environments 浓氨水环境中磷脂自组织的证据。

IF 2.8 3区生物学

Biochimica et biophysica acta. Biomembranes Pub Date : 2024-10-09 DOI: 10.1016/j.bbamem.2024.184391

Sean M. Mackay , Ben Sutherland , Richard A. Easingwood , Andrew Hopkins , Mihnea Bostina , Eng Wui Tan

引用次数: 0

Nanodisc-associated acetylcholinesterase as a novel model system of physiological relevant membrane-bound cholinesterases. Inhibition by phenolic compounds 纳米盘相关乙酰胆碱酯酶作为生理相关膜结合胆碱酯酶的新型模型系统。酚类化合物的抑制作用。

IF 2.8 3区生物学

Biochimica et biophysica acta. Biomembranes Pub Date : 2024-10-08 DOI: 10.1016/j.bbamem.2024.184389

Paula Belén Salazar , Fernando Gabriel Dupuy , Mariana C. Fiori , Samantha M. Stanfield , Jon McCord , Guillermo A. Altenberg , Carlos Javier Minahk

{"title":"Nanodisc-associated acetylcholinesterase as a novel model system of physiological relevant membrane-bound cholinesterases. Inhibition by phenolic compounds","authors":"Paula Belén Salazar , Fernando Gabriel Dupuy , Mariana C. Fiori , Samantha M. Stanfield , Jon McCord , Guillermo A. Altenberg , Carlos Javier Minahk","doi":"10.1016/j.bbamem.2024.184389","DOIUrl":"10.1016/j.bbamem.2024.184389","url":null,"abstract":"<div><div>Acetylcholinesterase (AChE) plays a pivotal role in the cholinergic system, and its inhibition is sought after in a wide range of applications, from insect control to Alzheimer's disease treatment. While the primary physiological isoforms of AChE are membrane-bound proteins, most assays for discovering new, safer, and potent inhibitors are conducted using commercially available soluble isoforms, such as the electric eel AChE (eeAChE). In this study, we conducted a comparative analysis of the activity and selectivity to phenolic inhibitors of recombinant human AChE, eeAChE and a mutant variant of human AChE known as dAChE4. Despite numerous mutations, dAChE4 closely resembles its parental protein and serves as a suitable model for monomeric human AChE. We also established an in vitro system of membrane-bound AChE to create a model that closely mimics the physiological isoforms. This system ensures the proper work of the enzyme and allowed us to control the exact concentration of enzyme and lipids per assay.</div></div>","PeriodicalId":8831,"journal":{"name":"Biochimica et biophysica acta. Biomembranes","volume":null,"pages":null},"PeriodicalIF":2.8,"publicationDate":"2024-10-08","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142387602","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