Biochimica et biophysica acta. Biomembranes最新文献_第2页

Successful strategies for expression and purification of ABC transporters 表达和纯化 ABC 转运体的成功策略。

IF 2.8 3区生物学 Q3 BIOCHEMISTRY & MOLECULAR BIOLOGY

Biochimica et biophysica acta. Biomembranes

Pub Date : 2024-11-12 DOI: 10.1016/j.bbamem.2024.184401

Bea Berner , Georgia Daoutsali , Emilia Melén , Natália Remper , Emma Weszelovszká , Alice Rothnie , Kristina Hedfalk

ATP-binding cassette (ABC) transporters are proteins responsible for active transport of various compounds, from small ions to macromolecules, across membranes. Proteins from this superfamily also pump drugs out of the cell resulting in multidrug resistance. Based on the cellular functions of ABC-transporters they are commonly associated with diseases like cancer and cystic fibrosis. To understand the molecular mechanism of this critical family of integral membrane proteins, structural characterization is a powerful tool which in turn requires successful recombinant production of stable and functional protein in good yields. In this review we have used high resolution structures of ABC transporters as a measure of successful protein production and summarized strategies for prokaryotic and eukaryotic proteins, respectively. In general, Escherichia coli is the most frequently used host for production of prokaryotic ABC transporters while human embryonic kidney 293 (HEK293) cells are the preferred host system for eukaryotic proteins. Independent of origin, at least two-steps of purification were required after solubilization in the most used detergent DDM. The purification tag was frequently cleaved off before structural characterization using cryogenic electron microscopy, or crystallization and X-ray analysis for prokaryotic proteins.

ATP结合盒（ABC）转运体是一种蛋白质，负责各种化合物（从小肠离子到大分子）的跨膜主动转运。该超家族的蛋白质还能将药物泵出细胞，从而产生多药耐药性。根据 ABC 转运体的细胞功能，它们通常与癌症和囊性纤维化等疾病有关。要了解这一重要的整体膜蛋白家族的分子机理，结构表征是一个强有力的工具，而这反过来又需要成功地重组生产稳定的功能性蛋白。在这篇综述中，我们将 ABC 转运体的高分辨率结构作为衡量成功生产蛋白质的标准，并分别总结了原核和真核蛋白质的生产策略。一般来说，大肠杆菌是生产原核 ABC 转运体最常用的宿主，而人胚肾 293（HEK293）细胞则是生产真核蛋白质的首选宿主系统。无论来源如何，在最常用的去垢剂 DDM 中溶解后至少需要两步纯化。在使用低温电子显微镜或结晶和 X 射线分析原核蛋白质的结构特征之前，纯化标签通常会被切掉。

{"title":"Successful strategies for expression and purification of ABC transporters","authors":"Bea Berner , Georgia Daoutsali , Emilia Melén , Natália Remper , Emma Weszelovszká , Alice Rothnie , Kristina Hedfalk","doi":"10.1016/j.bbamem.2024.184401","DOIUrl":"10.1016/j.bbamem.2024.184401","url":null,"abstract":"<div><div>ATP-binding cassette (ABC) transporters are proteins responsible for active transport of various compounds, from small ions to macromolecules, across membranes. Proteins from this superfamily also pump drugs out of the cell resulting in multidrug resistance. Based on the cellular functions of ABC-transporters they are commonly associated with diseases like cancer and cystic fibrosis. To understand the molecular mechanism of this critical family of integral membrane proteins, structural characterization is a powerful tool which in turn requires successful recombinant production of stable and functional protein in good yields. In this review we have used high resolution structures of ABC transporters as a measure of successful protein production and summarized strategies for prokaryotic and eukaryotic proteins, respectively. In general, <em>Escherichia coli</em> is the most frequently used host for production of prokaryotic ABC transporters while human embryonic kidney 293 (HEK293) cells are the preferred host system for eukaryotic proteins. Independent of origin, at least two-steps of purification were required after solubilization in the most used detergent DDM. The purification tag was frequently cleaved off before structural characterization using cryogenic electron microscopy, or crystallization and X-ray analysis for prokaryotic proteins.</div></div>","PeriodicalId":8831,"journal":{"name":"Biochimica et biophysica acta. Biomembranes","volume":"1867 2","pages":"Article 184401"},"PeriodicalIF":2.8,"publicationDate":"2024-11-12","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142614113","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

Bacterial flotillins as destabilizers of phospholipid membranes 作为磷脂膜脱稳剂的细菌絮凝物。

IF 2.8 3区生物学 Q3 BIOCHEMISTRY & MOLECULAR BIOLOGY

Biochimica et biophysica acta. Biomembranes

Pub Date : 2024-11-08 DOI: 10.1016/j.bbamem.2024.184399

Ana Álvarez-Mena , Estelle Morvan , Denis Martinez , Melanie Berbon , Abigail Savietto Scholz , Axelle Grélard , Sarah Turpin , Erick J. Dufourc , Marc Bramkamp , Birgit Habenstein

From archaea to mammals evolutionary conserved flotillins are scaffolding proteins, recognized for their nandomain-segregating activity. Flotillins form basket-like oligomeric architectures on the membrane, based on a conserved secondary structure composition of the monomeric subunits: a membrane-targeting region, an SPFH domain and a coiled-coil “flotillin” domain. In B. subtilis, the two flotillins FloT and FloA are present, localizing mainly in distinct nanodomains and executing multiple cellular functions. We here use deuterium and phosphorus solid-state NMR to monitor the effect of the different flotillins FloT and FloA and their structural components on model membranes. We find a clear disordering effect of FloT and FloA on the membranes reaching the carbon positions in the centre of the membrane. This effect is imposed by the hydrophobic region and the adjacent SPFH domain and, surprisingly, further supported by the membrane-distant flotillin domain. Biological implications of this disordering action are discussed.

从古生菌到哺乳动物，在进化过程中得到保护的绒毛膜蛋白是一种支架蛋白，因其具有核苷酸聚集活性而得到认可。基于单体亚基保守的二级结构组成：一个膜靶区、一个 SPFH 结构域和一个线圈 "flotillin "结构域，磷脂酰蛋白在膜上形成篮状寡聚体结构。在枯草芽孢杆菌中，存在 FloT 和 FloA 两种菌素，它们主要定位于不同的纳米域中，执行多种细胞功能。在此，我们利用氘和磷固态核磁共振来监测不同的FloT和FloA及其结构成分对模型膜的影响。我们发现 FloT 和 FloA 对到达膜中心碳位置的膜有明显的失调效应。这种作用是由疏水区域和邻近的 SPFH 结构域造成的，而且令人惊讶的是，这种作用还得到了膜远端 flotillin 结构域的进一步支持。本文讨论了这种紊乱作用的生物学意义。

{"title":"Bacterial flotillins as destabilizers of phospholipid membranes","authors":"Ana Álvarez-Mena , Estelle Morvan , Denis Martinez , Melanie Berbon , Abigail Savietto Scholz , Axelle Grélard , Sarah Turpin , Erick J. Dufourc , Marc Bramkamp , Birgit Habenstein","doi":"10.1016/j.bbamem.2024.184399","DOIUrl":"10.1016/j.bbamem.2024.184399","url":null,"abstract":"<div><div>From archaea to mammals evolutionary conserved flotillins are scaffolding proteins, recognized for their nandomain-segregating activity. Flotillins form basket-like oligomeric architectures on the membrane, based on a conserved secondary structure composition of the monomeric subunits: a membrane-targeting region, an SPFH domain and a coiled-coil “flotillin” domain. In <em>B. subtilis</em>, the two flotillins FloT and FloA are present, localizing mainly in distinct nanodomains and executing multiple cellular functions. We here use deuterium and phosphorus solid-state NMR to monitor the effect of the different flotillins FloT and FloA and their structural components on model membranes. We find a clear disordering effect of FloT and FloA on the membranes reaching the carbon positions in the centre of the membrane. This effect is imposed by the hydrophobic region and the adjacent SPFH domain and, surprisingly, further supported by the membrane-distant flotillin domain. Biological implications of this disordering action are discussed.</div></div>","PeriodicalId":8831,"journal":{"name":"Biochimica et biophysica acta. Biomembranes","volume":"1867 1","pages":"Article 184399"},"PeriodicalIF":2.8,"publicationDate":"2024-11-08","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142614074","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

Membrane fusion by dengue virus: The first step 登革热病毒的膜融合：第一步

IF 2.8 3区生物学 Q3 BIOCHEMISTRY & MOLECULAR BIOLOGY

Biochimica et biophysica acta. Biomembranes

Pub Date : 2024-11-08 DOI: 10.1016/j.bbamem.2024.184400

José Villalaín

Flaviviruses include important human pathogens such as Dengue, Zika, West Nile, Yellow fever, Japanese encephalitis, and Tick-borne encephalitis viruses as well as some emerging viruses that affect millions of people worldwide. They fuse their membrane with the late endosomal one in a pH-dependent way and therefore the merging of the membranes is one of the main goals for obtaining new antivirals. The envelope E protein, a membrane fusion protein, is accountable for fusion and encompasses different domains involved in the fusion mechanism, including the fusion peptide segment. In this work we have used molecular dynamics to study the interaction of the distal end of domain II of the DENV envelope E protein with a membrane like the late endosomal membrane in order to observe the initiation of membrane fusion carried out by a number of trimers of the DENV envelope E protein interacting with a complex biomembrane and demonstrate its feasibility. Our results demonstrate the likelihood of membrane disorganization and pore formation by trimer complex organization, the amino acids responsible for such condition and the secondary structure arrangements needed for such fundamental process. At the same time, we define new targets of the envelope E protein sequence which could permit designing potent antiviral bioactive molecules.

黄病毒包括登革热、寨卡、西尼罗河病毒、黄热病、日本脑炎、蜱传脑炎病毒等重要的人类病原体，以及一些影响全球数百万人的新出现的病毒。它们的膜与晚期内体膜融合的方式取决于 pH 值，因此膜的融合是获得新抗病毒药物的主要目标之一。包膜 E 蛋白是一种膜融合蛋白，它负责融合，并包含参与融合机制的不同结构域，包括融合肽段。在这项工作中，我们利用分子动力学研究了 DENV 包膜 E 蛋白结构域 II 的远端与类似晚期内体膜的膜的相互作用，以观察 DENV 包膜 E 蛋白的多个三聚体与复杂生物膜相互作用时膜融合的启动过程，并证明其可行性。我们的研究结果证明了三聚体复合物组织膜解构和孔形成的可能性、造成这种情况的氨基酸以及这种基本过程所需的二级结构排列。同时，我们还确定了包膜 E 蛋白序列的新目标，从而可以设计出强效的抗病毒生物活性分子。

{"title":"Membrane fusion by dengue virus: The first step","authors":"José Villalaín","doi":"10.1016/j.bbamem.2024.184400","DOIUrl":"10.1016/j.bbamem.2024.184400","url":null,"abstract":"<div><div>Flaviviruses include important human pathogens such as Dengue, Zika, West Nile, Yellow fever, Japanese encephalitis, and Tick-borne encephalitis viruses as well as some emerging viruses that affect millions of people worldwide. They fuse their membrane with the late endosomal one in a pH-dependent way and therefore the merging of the membranes is one of the main goals for obtaining new antivirals. The envelope E protein, a membrane fusion protein, is accountable for fusion and encompasses different domains involved in the fusion mechanism, including the fusion peptide segment. In this work we have used molecular dynamics to study the interaction of the distal end of domain II of the DENV envelope E protein with a membrane like the late endosomal membrane in order to observe the initiation of membrane fusion carried out by a number of trimers of the DENV envelope E protein interacting with a complex biomembrane and demonstrate its feasibility. Our results demonstrate the likelihood of membrane disorganization and pore formation by trimer complex organization, the amino acids responsible for such condition and the secondary structure arrangements needed for such fundamental process. At the same time, we define new targets of the envelope E protein sequence which could permit designing potent antiviral bioactive molecules.</div></div>","PeriodicalId":8831,"journal":{"name":"Biochimica et biophysica acta. Biomembranes","volume":"1867 1","pages":"Article 184400"},"PeriodicalIF":2.8,"publicationDate":"2024-11-08","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142614096","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

Antimicrobial and antibiofilm potential of α-MSH derived cationic and hydrophobic peptides against Escherichia coli: Mechanistic insight through peptide-lipopolysaccharide interactions α-MSH衍生的阳离子肽和疏水肽对大肠杆菌的抗菌和抗生物膜潜力：通过肽与脂多糖相互作用的机理研究。

IF 2.8 3区生物学 Q3 BIOCHEMISTRY & MOLECULAR BIOLOGY

Biochimica et biophysica acta. Biomembranes

Pub Date : 2024-11-07 DOI: 10.1016/j.bbamem.2024.184398

Priya Patel , Swaleeha Jaan Abdullah , Kanchan Tiwari , Surajit Bhattacharjya , Kasturi Mukhopadhyay

The prevalence of infections caused by various Gram-negative pathogens specifically Escherichia coli continuously poses a significant challenge in health care as well as community settings owing to their ability to form biofilm and escalating tolerance towards available antibiotics. While most treatment regimes are targeted at eliminating the E. coli cells, the pathogenicity factors called endotoxin (lipopolysaccharides), associated with the sepsis initiation and the leading cause of death in intensive care units globally, are often ignored. In this study, the potency of alpha-melanocyte stimulating hormone based-peptides, particularly Ana-9 and Ana-10 against E. coli was investigated through microbiological, biophysical, and microscopic assays. Both Ana-9 and Ana-10 demonstrated enhanced activity against planktonic E. coli cells, and retained their activity against biofilm, which was supported by confocal microscopy. From the mechanistic perspective, spectroscopic studies indicated that the binding of peptides with LPS led to structural alteration of peptides due to their insertion into the hydrophobic environment of LPS. The electrostatic interaction of the peptide with LPS leads to outer membrane disorganization, allowing the peptide to access the inner membrane, depolarize it and ultimately inhibit the bacterial cells within the biofilm. These observations were further confirmed by atomic force and scanning electron microscopy. Thus, this study deepens our understanding of the structural characteristics of peptides attached to LPS, which could lead to the gradual improvement in developing more potent, broad-spectrum endotoxin neutralizers.

由于各种革兰氏阴性病原体，特别是大肠埃希氏菌，具有形成生物膜的能力，而且对现有抗生素的耐受性不断提高，因此它们引起的感染在医疗保健和社区环境中持续流行，构成了一项重大挑战。虽然大多数治疗方案都以消灭大肠杆菌细胞为目标，但被称为内毒素（脂多糖）的致病因子却常常被忽视，而内毒素与败血症的发生有关，是全球重症监护室的主要死因。在这项研究中，我们通过微生物学、生物物理学和显微镜实验研究了基于α-黑色素细胞刺激素的肽，特别是 Ana-9 和 Ana-10 对大肠杆菌的作用。Ana-9 和 Ana-10 对浮游大肠杆菌细胞的活性增强，对生物膜的活性保持不变，共聚焦显微镜证实了这一点。从机理角度来看，光谱研究表明，肽与 LPS 结合后，由于肽插入到 LPS 的疏水环境中，导致肽的结构发生了改变。多肽与 LPS 的静电作用导致外膜紊乱，使多肽进入内膜，使内膜去极化，最终抑制生物膜内的细菌细胞。原子力和扫描电子显微镜进一步证实了这些观察结果。因此，这项研究加深了我们对附着在 LPS 上的肽的结构特征的了解，这将有助于逐步开发出更强效、更广谱的内毒素中和剂。

{"title":"Antimicrobial and antibiofilm potential of α-MSH derived cationic and hydrophobic peptides against Escherichia coli: Mechanistic insight through peptide-lipopolysaccharide interactions","authors":"Priya Patel , Swaleeha Jaan Abdullah , Kanchan Tiwari , Surajit Bhattacharjya , Kasturi Mukhopadhyay","doi":"10.1016/j.bbamem.2024.184398","DOIUrl":"10.1016/j.bbamem.2024.184398","url":null,"abstract":"<div><div>The prevalence of infections caused by various Gram-negative pathogens specifically <em>Escherichia coli</em> continuously poses a significant challenge in health care as well as community settings owing to their ability to form biofilm and escalating tolerance towards available antibiotics. While most treatment regimes are targeted at eliminating the <em>E. coli</em> cells, the pathogenicity factors called endotoxin (lipopolysaccharides), associated with the sepsis initiation and the leading cause of death in intensive care units globally, are often ignored. In this study, the potency of alpha-melanocyte stimulating hormone based-peptides, particularly Ana-9 and Ana-10 against <em>E. coli</em> was investigated through microbiological, biophysical, and microscopic assays. Both Ana-9 and Ana-10 demonstrated enhanced activity against planktonic <em>E. coli</em> cells, and retained their activity against biofilm, which was supported by confocal microscopy. From the mechanistic perspective, spectroscopic studies indicated that the binding of peptides with LPS led to structural alteration of peptides due to their insertion into the hydrophobic environment of LPS. The electrostatic interaction of the peptide with LPS leads to outer membrane disorganization, allowing the peptide to access the inner membrane, depolarize it and ultimately inhibit the bacterial cells within the biofilm. These observations were further confirmed by atomic force and scanning electron microscopy. Thus, this study deepens our understanding of the structural characteristics of peptides attached to LPS, which could lead to the gradual improvement in developing more potent, broad-spectrum endotoxin neutralizers.</div></div>","PeriodicalId":8831,"journal":{"name":"Biochimica et biophysica acta. Biomembranes","volume":"1867 1","pages":"Article 184398"},"PeriodicalIF":2.8,"publicationDate":"2024-11-07","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142614066","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

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 Q3 BIOCHEMISTRY & MOLECULAR BIOLOGY

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

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.

金黄色葡萄球菌很容易适应各种环境，并迅速产生抗生素耐药性，导致耐多药感染增加。因此，金黄色葡萄球菌是一个重大的全球健康问题，它对宿主环境的适应性对于了解发病机理和抗生素敏感性至关重要。当金黄色葡萄球菌以传统方式生长时，其膜脂质含有支链和直链饱和脂肪酸的混合物。然而，当生长培养基中含有不饱和脂肪酸时，它们就会成为总脂肪酸组成的主要部分。本研究探讨了在金黄色葡萄球菌膜脂中加入直链不饱和脂肪酸的生物物理效应。与仅在胰蛋白酶大豆肉汤中生长的培养物相比，添加了油酸的培养物膜制备物显示出更复杂的差示扫描量热扫描。在有油酸存在的情况下生长时，培养物会出现明显高于生长温度的转变，这归因于含有长链脂肪酸的糖脂的存在导致了双分子层内酰基链堆积失调。通过研究抗菌肽马斯托帕兰 X 诱导的单纤毛膜囊泡释放染料的动力学，评估了膜的功能方面。这些发现强调了生长环境、膜脂成分和细菌膜的物理特性之间错综复杂的关系，在开发抗金葡菌感染的新策略时应考虑到这一点。

{"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":"<div><div><em>Staphylococcus aureus</em> readily adapts to various environments and quickly develops antibiotic resistance, which has led to an increase in multidrug-resistant infections. Hence, <em>S. aureus</em> presents a significant global health issue and its adaptations to the host environment are crucial for understanding pathogenesis and antibiotic susceptibility. When <em>S. aureus</em> 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 <em>S. aureus</em> 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 <em>S. aureus</em> infections.</div></div>","PeriodicalId":8831,"journal":{"name":"Biochimica et biophysica acta. Biomembranes","volume":"1867 1","pages":"Article 184395"},"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 Q3 BIOCHEMISTRY & MOLECULAR BIOLOGY

Biochimica et biophysica acta. Biomembranes

Pub Date : 2024-10-30 DOI: 10.1016/j.bbamem.2024.184396

Takafumi Kawai , Natsuki Mizutani , Yasushi Okamura

Phosphatidylinositol 4,5-bisphosphate (PIP₂) is a key membrane lipid regulating various ion channel activities. Currently, several molecular tools are used to modulate PIP₂ levels, each of which has distinct advantages and drawbacks. In this study, we proposed a novel methodology using heterologous Xenopus oocytes to precisely manipulate PIP₂ levels using phospholipase C (PLC)-ζ, which hydrolyzes PIP₂. Xenopus oocytes injected with PLCζ exhibited notable hyperpolarization-induced Ca²⁺ influx driven by the increased driving force of Ca²⁺. High Ca²⁺ sensitivity of PLCζ facilitated hyperpolarization-induced PLC activity in Xenopus oocytes that was voltage- and Ca²⁺-dependent. This study demonstrated the regulatory capacity of PLCζ in modulating PIP₂-sensitive ion channels, such as the KCNQ2/3 and GIRK channels, in a voltage- and Ca²⁺-dependent manner. Moreover, activation pathway of PLCζ only requires a two-electrode voltage clamp setup, making it a convenient molecular tool to manipulate PIP₂ 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 PIP₂ levels, (2) PIP₂ levels were decreased without any increase in phosphatidylinositol 4-monophosphate (PIP) levels, and (3) PIP₂ levels were reduced by Ca²⁺ administration. Therefore, PLCζ effectively supports understanding how PIP₂ regulates ion channels, alongside VSP. Overall, this study highlights the unique characteristics of PLCζ and its distinct advantages in analyzing ion channel regulation by PIP₂ and the PLC pathway in Xenopus oocytes.

磷脂酰肌醇 4,5-二磷酸（PIP2）是调节各种离子通道活动的关键膜脂。目前，有多种分子工具可用于调节 PIP2 的水平，但每种工具都有各自的优缺点。在本研究中，我们提出了一种利用异源爪蟾卵母细胞的新方法，即利用能水解 PIP2 的磷脂酶 C（PLC）-ζ 来精确操纵 PIP2 水平。注射了 PLCζ 的爪蟾卵母细胞在 Ca2+ 驱动力增加的驱动下表现出明显的超极化诱导 Ca2+ 流入。PLCζ 对 Ca2+ 的高敏感性促进了超极化诱导的 PLC 在章鱼卵母细胞中的活性，这种活性是电压和 Ca2+ 依赖性的。这项研究证明了 PLCζ 以电压和 Ca2+ 依赖性方式调节 PIP2 敏感离子通道（如 KCNQ2/3 和 GIRK 通道）的调节能力。此外，PLCζ的激活途径只需要一个双电极电压钳装置，这使其成为一种方便的分子工具，可与电压感应磷酸酶（VSP）相结合来操纵 PIP2 水平。与 VSP 相比，PLCζ 具有明显的特点和优势：(1) 超极化（而非去极化）会降低 PIP2 水平；(2) PIP2 水平降低的同时，磷脂酰肌醇 4-单磷酸（PIP）水平不会增加；(3) 施加 Ca2+ 会降低 PIP2 水平。因此，PLCζ 有效地支持了对 PIP2 如何与 VSP 一起调节离子通道的理解。总之，本研究强调了 PLCζ 的独特性及其在分析异种卵母细胞中 PIP2 和 PLC 通路对离子通道调控的独特优势。

{"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":"1867 1","pages":"Article 184396"},"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

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 Q3 BIOCHEMISTRY & MOLECULAR BIOLOGY

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

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.

离子液体（ILs）具有渗透和穿透脂质双分子层的能力，与抗菌效果相关，因此被研究用作抗生素制剂的潜在成分。脂肪酸基 IL（FAILs）中的阴离子是长链脂肪酸，可以渗透脂膜，由于对人体细胞的细胞毒性较低，因此已被用于生物医学领域。在这项工作中，我们研究了几种不同的 FAILs 对脂质双分子层的渗透能力，以及这种渗透能力与抗菌活性、细胞膜渗透性和细胞毒性之间的关系。FAIL 由阳离子四甲基胍（TMG）或胆碱与辛酸酯或癸酸酯组合而成。在具有三种不同脂质成分的模型双层囊泡上对这些 FAIL 进行了测试，使用渗漏测定法检测其膜渗透性。然后在细菌和哺乳动物细胞上进行了抗生素和膜渗透测试。结果表明，辛酸酯类 FAIL 不能形成胶束，对囊泡和生物细胞的活性较低，而癸酸酯类 FAIL 则能渗透双层膜，并具有与模型囊泡结果相关的生物活性。同时具有阳离子和脂肪酸阴离子的IL具有很强的活性，而单独的癸酸酯只有极低的渗透性和抗生素活性。当 FAIL 的浓度低于其 CMC 值时就会发生膜渗透，这表明它们的作用机制可能不涉及胶束的形成。

{"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":"1867 1","pages":"Article 184393"},"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 Q3 BIOCHEMISTRY & MOLECULAR BIOLOGY

Biochimica et biophysica acta. Biomembranes

Pub Date : 2024-10-22 DOI: 10.1016/j.bbamem.2024.184394

Chih Hung Lo

Tumor necrosis factor receptors (TNFR1 and TNFR2) play key roles in mediating inflammatory response and cell death signaling, which are associated with autoimmune disorders, neurodegenerative diseases, and cancers. The structure-function relationships of TNF receptors and their ligands determine the activation or inhibition of downstream signaling pathways. Available crystal structures have provided critical insights into the therapeutic targeting strategies of TNF receptors and their signaling networks. In this review, we discuss the potential of targeting receptor-ligand and receptor-receptor interactions in a competitive manner as well as perturbing receptor conformational dynamics through an allosteric mechanism to modulate TNF receptor signaling. We propose that conformational states of TNF receptors can act as a molecular switch in determining their functions and are important therapeutic targets. The knowledge of the structure-function relationships of TNF receptors can be applied to translational high-throughput drug screening and design of novel receptor-specific modulators with enhanced pharmacological properties.

肿瘤坏死因子受体（TNFR1 和 TNFR2）在介导炎症反应和细胞死亡信号传导方面发挥着关键作用，而炎症反应和细胞死亡信号传导与自身免疫性疾病、神经退行性疾病和癌症有关。TNF 受体及其配体的结构-功能关系决定了下游信号通路的激活或抑制。现有的晶体结构为 TNF 受体及其信号网络的靶向治疗策略提供了重要见解。在这篇综述中，我们讨论了以竞争方式靶向受体-配体和受体-受体相互作用的潜力，以及通过异构机制扰乱受体构象动力学以调节 TNF 受体信号传导的潜力。我们提出，TNF受体的构象状态可作为决定其功能的分子开关，是重要的治疗靶点。有关 TNF 受体结构-功能关系的知识可应用于转化型高通量药物筛选，并设计出药理特性更强的新型受体特异性调节剂。

{"title":"TNF receptors: Structure-function relationships and therapeutic targeting strategies","authors":"Chih Hung Lo","doi":"10.1016/j.bbamem.2024.184394","DOIUrl":"10.1016/j.bbamem.2024.184394","url":null,"abstract":"<div><div>Tumor necrosis factor receptors (TNFR1 and TNFR2) play key roles in mediating inflammatory response and cell death signaling, which are associated with autoimmune disorders, neurodegenerative diseases, and cancers. The structure-function relationships of TNF receptors and their ligands determine the activation or inhibition of downstream signaling pathways. Available crystal structures have provided critical insights into the therapeutic targeting strategies of TNF receptors and their signaling networks. In this review, we discuss the potential of targeting receptor-ligand and receptor-receptor interactions in a competitive manner as well as perturbing receptor conformational dynamics through an allosteric mechanism to modulate TNF receptor signaling. We propose that conformational states of TNF receptors can act as a molecular switch in determining their functions and are important therapeutic targets. The knowledge of the structure-function relationships of TNF receptors can be applied to translational high-throughput drug screening and design of novel receptor-specific modulators with enhanced pharmacological properties.</div></div>","PeriodicalId":8831,"journal":{"name":"Biochimica et biophysica acta. Biomembranes","volume":"1867 1","pages":"Article 184394"},"PeriodicalIF":2.8,"publicationDate":"2024-10-22","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142493944","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

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 Q3 BIOCHEMISTRY & MOLECULAR BIOLOGY

Biochimica et biophysica acta. Biomembranes

Pub Date : 2024-10-17 DOI: 10.1016/j.bbamem.2024.184387

Kyriakos Georgiou, Antonios Kolocouris

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.

97个残基的甲型流感基质2（ΑM2）蛋白是病毒蛋白的原型，它通过水分子和His37转运质子。我们讨论了结构生物学和分子生物物理学实验以及一些功能测定，这些实验和测定在过去 40 年中改变了我们对 AM2 结构和功能的理解。对ΑM2的结构研究是在不同条件（pH值、温度、脂质、构建体）下进行的，并使用了不同的蛋白质构建体，如AM2跨膜（AM2TM）结构域、AM2传导结构域（AM2CD）、含外结构域或外结构域截断、AM2全长（AM2FL），旨在描述AM2稳定性和功能所必需的不同构象和结构细节。然而，这些实验的结论有时显得模棱两可，引起了激烈的争论。这并不是因为测量结果不准确，而是因为使用了不同的膜模拟环境，如去垢剂、胶束或磷脂双分子层，使用了不同的方法（如 X 射线晶体学、固态核磁共振、溶液核磁共振、原生质谱），构建了不同的蛋白质（如 AM2TM 或 AM2CD），或跟踪了不同的氨基酸残基。我们根据所使用的不同生物物理方法、研究小组来介绍这些成果，并通常按照时间顺序介绍研究进展。我们讨论了对 AM2 结构细节进行更多研究的想法，以及目前的发现如何有助于探索抑制甲型流感的新途径。AM2的研究可以为研究其他作为药物靶点的病毒蛋白提供灵感。

{"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":"1867 1","pages":"Article 184387"},"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 Q3 BIOCHEMISTRY & MOLECULAR BIOLOGY

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

Polymer nanodiscs are an attractive alternative to surfactants for studying integral membrane proteins within their native lipid environment. Here, we investigate the use of such polymers to isolate a computationally-designed de novo membrane cytochrome named CytbX. We show that the block copolymers known as CyclAPols can efficiently extract CytbX directly from biomembranes and are compatible with the downstream purification and biophysical characterisation of this artificial protein. CyclAPol-solubilised CytbX is well-folded and highly robust with properties that are essentially identical to those observed for the same protein in a detergent micelle. However, electron transfer to CytbX from a diffusive flavoprotein is substantially faster in micelles than in the nanodisc system. Our results confirm that polymer nanodiscs will be a useful tool for the ongoing study and application of de novo membrane proteins.

在研究原生脂质环境中的整体膜蛋白时，聚合物纳米盘是一种极具吸引力的表面活性剂替代品。在这里，我们研究了如何利用这种聚合物来分离一种通过计算重新设计的膜细胞色素 CytbX。我们的研究表明，被称为 CyclAPols 的嵌段共聚物能直接从生物膜中有效地提取 CytbX，并能与这种人工蛋白的下游纯化和生物物理特性分析相兼容。CyclAPol溶解后的CytbX具有良好的折叠性和高度的稳健性，其特性与在洗涤剂胶束中观察到的相同蛋白质的特性基本相同。然而，在胶束中，扩散黄素蛋白向 CytbX 的电子传递速度远远快于纳米盘系统。我们的研究结果证实，聚合物纳米盘将成为研究和应用新膜蛋白的有用工具。

引用次数: 0