Chemistry and Physics of Lipids最新文献

{"title":"Interaction of biomimetic lipid membranes with detergents with different physicochemical characteristics.","authors":"Mariana S S Oliveira, Amanda C Caritá, Karin A Riske","doi":"10.1016/j.chemphyslip.2025.105473","DOIUrl":"https://doi.org/10.1016/j.chemphyslip.2025.105473","url":null,"abstract":"<p><p>Membrane solubilization by detergents is routinely performed to separate membrane components, and to extract and purify membrane proteins. This process depends both on the characteristics of the detergent and properties of the membrane. Here we investigate the interaction of eight detergents with very distinct physicochemical features with model membranes in different biologically relevant phases. The detergents chosen were the non-ionic Triton X-100, Triton X-165, C10E5, octyl glucopyranoside (OG) and dodecyl maltoside (DDM) and the ionic sodium dodecyl sulfate (SDS), cetyl trimethyl ammonium bromide (CTAB) and Chaps. Three lipid compositions were explored: pure palmitoyl oleoyl phosphatidylcholine (POPC), in the liquid-disordered (Ld) phase, sphingomyelin (SM)/cholesterol 7:3 (chol) in the liquid-ordered (Lo) phase and the biomimetic POPC/SM/chol 2:1:2, which might exhibit Lo/Ld phase separation. Turbidity measurements of small liposomes were performed along the titration with the detergents to obtain the overall solubilization profiles and optical microscopy of giant unilamellar vesicles (GUVs) was used to reveal the mechanism of interaction of the detergents. The presence of cholesterol renders the membranes partly/fully insoluble in all detergents, and the charged detergents are the least effective to solubilize POPC. The non-ionic detergents, with exception of DDM, with the bulkiest headgroup, caused a substantial increase in surface area of POPC, which was quantified directly on single GUVs. The other detergents induced mainly vesicle burst. Detergents that caused some increase in area induced Lo/Ld phase separation in the ternary mixture, with preferential solubilization of the latter. The insoluble area fraction left intact was quantified. Overall, the non-ionic detergents were the most effective in solubilizing lipid membranes.</p>","PeriodicalId":275,"journal":{"name":"Chemistry and Physics of Lipids","volume":" ","pages":"105473"},"PeriodicalIF":3.4,"publicationDate":"2025-01-31","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143078088","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}

{"title":"Broad-based targeted lipidomic analysis of dental fluorosis population in an adult population","authors":"Huiying Kong ,&nbsp;Shanshan Liu ,&nbsp;Zhenzhen Li ,&nbsp;Li Xu ,&nbsp;Kai Zhang ,&nbsp;Yuanyin Wang","doi":"10.1016/j.chemphyslip.2025.105471","DOIUrl":"10.1016/j.chemphyslip.2025.105471","url":null,"abstract":"<div><div>Dental fluorosis, as a common chronic fluoride toxicity oral disease, is mainly caused by long-term excessive intake of fluoride, which seriously affects the aesthetics and function of patients' teeth. In recent years, with the rapid development of metabolomics technology, lipidomics, as an important means to study the changes in lipid metabolism in organisms, has shown great potential in revealing the mechanisms of disease development. As a major component of cell membranes and a signaling molecule, metabolic disorders of lipids are closely related to a variety of diseases, but the specific mechanism of action in dental fluorosis is still unclear. Therefore, the present study aimed to systematically analyze the differences in lipid profiles between dental fluorosis patients and healthy populations by using broad-based targeted lipidomics technology to provide new perspectives on the pathogenesis of dental fluorosis. To this end, the researchers compared the salivary lipidome of healthy participants with the salivary micro lipidome of dental fluorosis patients. Their saliva samples were collected, and advanced broad-based targeted lipidomics technology, combined with a high-performance liquid chromatography-mass spectrometry (LC-MS) system, was used to comprehensively detect and quantify the lipids in the samples. The lipid data were processed and analyzed by bioinformatics to identify the unique patterns of changes in the lipid profiles of dental fluorosis patients and to verify the significance of these changes using statistical methods. Several glycerophospholipids, fatty acyls, and sphingolipids exhibited marked alterations in dental Among these, glycocholic acid, LPA (18:4), taurolithocholic acid-3-sulfate, lithocholic acid-3-sulfate, and taurochenodeoxycholic acid-3-sulfate were observed between dental fluorosis patients and healthy controls. taurochenodeoxycholic acid was significantly decreased, while PA (12:0_12:0) levels were significantly elevated. These findings suggest that These findings suggest that disturbances in lipid metabolism play a crucial role in developing dental fluorosis.</div></div>","PeriodicalId":275,"journal":{"name":"Chemistry and Physics of Lipids","volume":"267 ","pages":"Article 105471"},"PeriodicalIF":3.4,"publicationDate":"2025-01-09","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142963388","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}

{"title":"Electrophysiological dissection of the ion channel activity of the Pseudomonas aeruginosa ionophore protein toxin Tse5","authors":"Jessica Rojas-Palomino ,&nbsp;Jon Altuna-Alvarez ,&nbsp;Amaia González-Magaña ,&nbsp;María Queralt-Martín ,&nbsp;David Albesa-Jové ,&nbsp;Antonio Alcaraz","doi":"10.1016/j.chemphyslip.2025.105472","DOIUrl":"10.1016/j.chemphyslip.2025.105472","url":null,"abstract":"<div><div>We present an in-depth electrophysiological analysis of Tse5, a pore-forming toxin (PFT) delivered by the type VI secretion system (T6SS) of <em>Pseudomonas aeruginosa</em>. The T6SS is a sophisticated bacterial secretion system that injects toxic effector proteins into competing bacteria or host cells, providing a competitive advantage by disabling other microbes and modulating their environment. Our findings highlight the dependency of Tse5 insertion on membrane charge and electrolyte concentration, suggesting an in vivo effect from the periplasmic space. Conductance and selectivity experiments reveal a predominant and reproducible pore architecture of Tse5, characterized by a weak cation selectivity without chemical specificity. pH titration experiments suggest a proteolipidic pore structure influenced by both protein and lipid charges, a hypothesis further supported by experiments involving engineered mutants of Tse5 with altered glycine zippers. These results significantly advance our understanding of Tse5's molecular mechanism of toxicity, paving the way for potential applications in biosensing and macromolecular delivery.</div></div>","PeriodicalId":275,"journal":{"name":"Chemistry and Physics of Lipids","volume":"267 ","pages":"Article 105472"},"PeriodicalIF":3.4,"publicationDate":"2025-01-06","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142942103","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}

{"title":"Laurdan in living cells: Where do we stand?","authors":"L. Stefania Vargas-Velez ,&nbsp;Natalia Wilke","doi":"10.1016/j.chemphyslip.2024.105458","DOIUrl":"10.1016/j.chemphyslip.2024.105458","url":null,"abstract":"<div><div>Laurdan is a valuable tool for analyzing phase transitions and general behavior in synthetic lipid membranes. Its use is very straightforward, thus, its application in cells has expanded rapidly in recent years. It has been demonstrated that Laurdan is very useful for analyzing membrane trends when cells are subjected to some treatment, or when different cell mutations are compared. However, a deep interpretation of the data is not as straightforward as in synthetic lipid bilayers. In this review, we complied results found in mammalian and bacterial cells and noted that the use of Laurdan could be improved if a comparison between publications could be done. At the moment this is not easy, mainly due to the lack of complete information in the publications, and to the different methodologies employed in the data recording and processing. We conclude that research in cell membrane topics would benefit from a better use of the Laurdan probe.</div></div>","PeriodicalId":275,"journal":{"name":"Chemistry and Physics of Lipids","volume":"266 ","pages":"Article 105458"},"PeriodicalIF":3.4,"publicationDate":"2025-01-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142737915","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}

{"title":"Effect of hydrophobic proteins in modulating the mechanical properties of lung surfactant membranes","authors":"Ainhoa Collada ,&nbsp;Johann Mertens ,&nbsp;Emma Batllori-Badia ,&nbsp;Alberto Galindo ,&nbsp;Antonio Cruz ,&nbsp;Jesús Pérez-Gil","doi":"10.1016/j.chemphyslip.2024.105464","DOIUrl":"10.1016/j.chemphyslip.2024.105464","url":null,"abstract":"<div><div>Pulmonary surfactant is a membranous complex that enables breathing dynamics at the respiratory surface. Extremely low values of surface tension are achieved at end-expiration thanks to a unique mixture of lipids and proteins. In particular, the hydrophobic surfactant proteins, specially the protein SP-B, are crucial for surfactant biophysical function, in order to provide the surfactant lipid matrix with the ability to form membranous multi-layered interfacial films that sustain optimal mechanical properties. To analyse the contribution of the proteins to modulate the resistance to mechanical forces of surfactant membrane-based structures, atomic force microscopy of supported lipid bilayers has been used here to determine quantitative mechanical parameters defining the effect of the presence of proteins SP-B and/or SP-C on phospholipid membranes intended to model at least part of the structures integrated into pulmonary surfactant complexes. The results show clear differences introduced by proteins in membrane thickness, lateral packing and elasticity, providing evidence supporting protein-promoted modulating of the mechanical properties of surfactant membranes. These effects are found consistent with the behaviour of two relevant native materials: whole pulmonary surfactant isolated from porcine bronchoalveolar lavages and freshly produced human pulmonary surfactant isolated from amniotic fluid, where it is transferred from the foetal lung before the respiratory air-liquid interface has been established.</div></div>","PeriodicalId":275,"journal":{"name":"Chemistry and Physics of Lipids","volume":"267 ","pages":"Article 105464"},"PeriodicalIF":3.4,"publicationDate":"2024-12-21","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142880716","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}

{"title":"The mechanical properties of nerves, the size of the action potential, and consequences for the brain","authors":"Thomas Heimburg","doi":"10.1016/j.chemphyslip.2024.105461","DOIUrl":"10.1016/j.chemphyslip.2024.105461","url":null,"abstract":"<div><div>The action potential is widely regarded as a purely electrical phenomenon. However, one also finds mechanical and thermal changes that can be observed experimentally. In particular, nerve membranes become thicker and axons contract. The spatial length of the action potential can be quite large, ranging from millimeters to many centimeters. This suggests the use of macroscopic thermodynamics methods to understand its properties. The pulse length is several orders of magnitude larger than the synaptic gap, larger than the distance of the nodes of Ranvier and even larger than the size of many neurons such as pyramidal cells or brain stem motor neurons. Here, we review the mechanical changes in nerves, we discuss theoretical possibilities to explain them and implications of a mechanical nerve pulse for neurons and for the brain. In particular, the contraction of nerves leads to the possibility of fast mechanical synapses.</div></div>","PeriodicalId":275,"journal":{"name":"Chemistry and Physics of Lipids","volume":"267 ","pages":"Article 105461"},"PeriodicalIF":3.4,"publicationDate":"2024-11-30","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142764908","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}

{"title":"Modifications of biological membranes, fat globules and liposomes promoted by cavitation processes. Consequences and applications","authors":"Santiago Fleite ,&nbsp;Miryan Cassanello ,&nbsp;María del Pilar Buera","doi":"10.1016/j.chemphyslip.2024.105462","DOIUrl":"10.1016/j.chemphyslip.2024.105462","url":null,"abstract":"<div><div>Cavitation-based technologies, such as ultrasound (or acoustic cavitation, AC) and hydrodynamic cavitation (HC), are gaining interest among green processing technologies due to their cost effectiveness in operation, toxic solvent use reduction, and ability to obtain superior processed products, compared to conventional methods. Both AC and HC generate bubbles, but their effects may differ and it is difficult to make comparisons as both are based on different phenomena and are subject to different operational variables. AC is one of the most used techniques in extraction and homogenization processes at the laboratory level. However, upscaling to an industrial level is hard. On the other hand, HC is based on the passage of the liquid through a constriction (orifice plate, Venturi, throttling valve), which causes an increase in liquid velocity at the expense of local pressure, forcing the pressure around the contraction below the threshold pressure that induces the formation of cavities. Some applications of cavitation technologies, such as the production of liposomes or lipid nanoparticles (LNPs) allow the generation of delivery systems for biomedical applications.Many others (inactivation of pathogenic viruses, bacteria and algae for water purification, extraction procedures, third generation of biofuel production, green extractions) are based on the disruption of lipid membranes. There are also applications aimed at the modification of membranes (like the milk fat globule) for the development of innovative products. Process parameters, such as cavitation intensity, duration and temperature define the impact of the process on the physical, chemical, and biological characteristics of the membranes. Thus, the adequate implementation of cavitation processes requires understanding of interactions and synergistic mechanisms in complex systems and of their effects on membranes at the microscopic or molecular level. In the present work, the use of cavitation technologies for the generation of LNPs or nanostructured lipid carriers, and the effects of AC and HC treatments on several types of membrane systems (liposomes, solid lipid nanoparticles, milk fat globules, algae and bacterial membranes) are discussed, focusing on the structural and chemical modifications of lipidic structures under cavitation.</div></div>","PeriodicalId":275,"journal":{"name":"Chemistry and Physics of Lipids","volume":"267 ","pages":"Article 105462"},"PeriodicalIF":3.4,"publicationDate":"2024-11-30","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142764901","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}

{"title":"The pleomorphic cholesterol sensing motifs of transmembrane proteins","authors":"Francisco J. Barrantes","doi":"10.1016/j.chemphyslip.2024.105460","DOIUrl":"10.1016/j.chemphyslip.2024.105460","url":null,"abstract":"<div><div>Millions of years of phylogenetic evolution have shaped the crosstalk between sterols and membrane-embedded proteins. This lengthy process, which began before the appearance of eukaryotic cells, has sculpted the two types of molecules to cover a wide spectrum of structural interconnectedness, ranging from rapid touch-and-go hits of low-affinity between surfaces to stronger lock-and-key type structural contacts. The former usually involve relatively loose contacts between linear amino acid sequences on the membrane-exposed transmembrane domains of the protein, readily accessible to the sterols as they briefly visit clefts between adjacent transmembrane segments while in rapid exchange with the bulk lipid bilayer. This operational mode is probably the most ancestral one, since it was already present in primitive bacteria interacting with hopanoid lipids. At the other end of this spectrum are more complex cholesterol binding sites that have required the acquisition of complex 3D non-sequential segments of the membrane protein to establish stereochemically elaborate 3D designs complementary to the rough and smooth surfaces of the eukaryotic neutral lipid, cholesterol. This short review explores cholesterol-membrane protein interactions using membrane protein paradigms having in common their participation in intercellular communications neurotransmission, hormone signalling, amino acid/neurotransmitter transport- and in cancer.</div></div>","PeriodicalId":275,"journal":{"name":"Chemistry and Physics of Lipids","volume":"266 ","pages":"Article 105460"},"PeriodicalIF":3.4,"publicationDate":"2024-11-29","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142757152","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}

{"title":"Studying the interfacial activity and structure of pulmonary surfactant complexes","authors":"Ainhoa Collada,&nbsp;Antonio Cruz,&nbsp;Jesús Pérez-Gil","doi":"10.1016/j.chemphyslip.2024.105459","DOIUrl":"10.1016/j.chemphyslip.2024.105459","url":null,"abstract":"<div><div>Pulmonary surfactant (PS) is a membranous complex that coats the respiratory air-liquid interface in air-breathing animal lungs. Its main function is to minimize the surface tension at the end of expiration, what is needed for preventing alveolar collapse. Although the tension reduction capabilities of surfactant depend on the formation of air-exposed phospholipid-enriched monolayers, the interfacial surfactant films are far from simple monolayers. Surfactant surface films are dynamically interconnected to continuously secreted newly synthetized material thanks to the action of a pair of very hydrophobic proteins, termed SP-B and SP-C, which are responsible to modulate the biophysical behavior of the complex. Other proteins in the system, such as the hydrophilic SP-A and SP-D, are integrated into different surfactant structures but participate primarily in the immune defense of the lung. In spite of countless studies on the structure and chemico-physical properties of surfactant membranes, the full complexity of surfactant three-dimensional structure is far from being completely understood. Here we review some of the most useful techniques that have allowed the characterization of the PS system along the years to develop the current models interpreting surfactant structure-function relationships.</div></div>","PeriodicalId":275,"journal":{"name":"Chemistry and Physics of Lipids","volume":"266 ","pages":"Article 105459"},"PeriodicalIF":3.4,"publicationDate":"2024-11-23","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142708828","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}

{"title":"Use of stable isotope-labeled fatty acids to measure desaturase activities with negative chemical ionization GC-MS","authors":"Youenn Launay ,&nbsp;Iwan Jan ,&nbsp;Vincent Ciesielski ,&nbsp;Lydie Hue ,&nbsp;Mélodie Succar ,&nbsp;Léa Fret ,&nbsp;Thomas Guerbette ,&nbsp;Karima Begriche ,&nbsp;Philippe Legrand ,&nbsp;Daniel Catheline ,&nbsp;Manuel Vlach ,&nbsp;Vincent Rioux","doi":"10.1016/j.chemphyslip.2024.105451","DOIUrl":"10.1016/j.chemphyslip.2024.105451","url":null,"abstract":"<div><div>Fatty acid desaturases are key enzymes in lipid metabolism. They introduce double bonds between defined carbons of the fatty acyl chain and catalyze rate-limiting steps in the biosynthesis of polyunsaturated fatty acids. For decades, <em>in vitro</em> desaturase activities have been determined by using radiolabeled fatty acids as substrates, incubated with tissue or cell fractions containing membrane-bound desaturases. However, handling radioactivity is being increasingly complicated due to safety and regulatory concern. Radiolabeled fatty acids are also expensive and many of them are not commercially available. There is therefore a crucial need to develop new methods. Although methods using unlabeled fatty acids as substrates have recently been validated, they are well suited for large tissue samples and did not achieve the same sensitivity as the radioactive ones. Here, we show that negative chemical ionization GC-MS on stable isotope-labeled fatty acids, derivatized to pentafluorobenzyl esters, now offers this opportunity, because of its high sensitivity in the selected ion monitoring mode. By using this simple and affordable improved method, we measured the kinetic parameters of mouse liver Δ6-desaturase for its two main substrates (C18:2 n-6 and C18:3 n-3; 10–13 µM). Moreover, this method enabled to compare Δ5-desaturase apparent Km values (19–22 µM) for its two main substrates (C20:3 n-6 and C20:4 n-3). Finally, we re-evaluated the controversial effect of freezing on desaturase activities by using both frozen rat tissues and cryopreserved human hepatocytes. This safe, reliable and sensitive method may be applied to other enzymatic activities involving fatty acids (elongation, hydroxylation) in miniaturized samples.</div></div>","PeriodicalId":275,"journal":{"name":"Chemistry and Physics of Lipids","volume":"266 ","pages":"Article 105451"},"PeriodicalIF":3.4,"publicationDate":"2024-11-08","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142610800","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}