The European Physical Journal E最新文献

{"title":"Spontaneous bilayer wrapping of virus particles by a phospholipid Langmuir monolayer","authors":"J. F. Torres-Salgado,&nbsp;M. V. Villagrana-Escareño,&nbsp;A. L. Duran-Meza,&nbsp;X. F. Segovia-Gonzalez,&nbsp;R. D. Cadena-Nava,&nbsp;W. M. Gelbart,&nbsp;C. M. Knobler,&nbsp;J. Ruiz-García","doi":"10.1140/epje/s10189-023-00366-8","DOIUrl":"10.1140/epje/s10189-023-00366-8","url":null,"abstract":"<div><p>We report here the spontaneous formation of lipid-bilayer-wrapped virus particles, following the injection of “naked” virus particles into the subphase of a Langmuir trough with a liquid monolayer of lipids at its air–water interface. The virus particles are those of the well-studied cowpea chlorotic mottle virus, CCMV, which are negatively charged at the pH 6 of the subphase; the lipids are a 9:1 mix of neutral DMPC and cationic CTAB molecules. Before adding CCMV particles to the subphase we establish the mixed lipid monolayer in its liquid-expanded state at a fixed pressure (17.5 mN/m) and average area-per-molecule of (41Ų). Keeping the total area fixed, the surface pressure is observed to decrease at about 15 h after adding the virus particles in the subphase; by 37 h it has dropped to zero, corresponding to essentially all the lipid molecules having been removed from the air–water interface. By collecting particles from the subphase and measuring their sizes by atomic force microscopy, we show that the virus particles have been wrapped by lipid bilayers (or by two lipid bilayers). These results can be understood in terms of thermal fluctuations and electrostatic interactions driving the wrapping of the anionic virus particles by the cationic lipids.</p><h3>Graphical Abstract</h3><div><figure><div><div><picture><source><img></source></picture></div><div><p>Spontaneous acquisition by a virus particle of, first, a hydrophobic lipid monolayer envelope and, then, a hydrophilic lipid bilayer envelope, as it interacts from the subphase with an oppositely charged Langmuir monolayer</p></div></div></figure></div></div>","PeriodicalId":790,"journal":{"name":"The European Physical Journal E","volume":"46 12","pages":""},"PeriodicalIF":1.8,"publicationDate":"2023-12-05","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://link.springer.com/content/pdf/10.1140/epje/s10189-023-00366-8.pdf","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"138486371","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":4,"RegionCategory":"物理与天体物理","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"OA","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Effective interactions and phase behavior of protein solutions in the presence of hexamine cobalt(III) chloride","authors":"Maximilian D. Senft,&nbsp;Ralph Maier,&nbsp;Anusha Hiremath,&nbsp;Fajun Zhang,&nbsp;Frank Schreiber","doi":"10.1140/epje/s10189-023-00376-6","DOIUrl":"10.1140/epje/s10189-023-00376-6","url":null,"abstract":"<div><p>It is well established that deoxyribonucleic acid (DNA) and ribonucleic acid (RNA) exhibit a reentrant condensation (RC) phase behavior in the presence of the trivalent hexamine cobalt(III) cations (Hac) which can be important for their packing and folding. A similar behavior can be observed for negatively charged globular proteins in the presence of trivalent metal cations, such as Y³⁺ or La³⁺. This phase behavior is mainly driven by charge inversion upon an increasing salt concentration for a fixed protein concentration (<i>c</i>_p). However, as Hac exhibits structural differences compared to other multivalent metal cations, with six ammonia ligands (NH₃) covalently bonded to the central cobalt atom, it is not clear that Hac can induce a similar phase behavior for proteins. In this work, we systematically investigate whether negatively charged globular proteins β-lactoglobulin (BLG), bovine serum albumin (BSA), human serum albumin (HSA) and ovalbumin (OVA) feature Hac-induced RC. Effective protein–protein interactions were investigated by small-angle X-ray scattering. The reduced second virial coefficient (B₂/B₂^HS) was obtained as a function of salt concentration. The virial coefficient analysis performed confirms the reentrant interaction (RI) behavior for BLG without actually inducing RC, given the insufficient strengths of the interactions for the latter to occur. In contrast, the strength of attraction for BSA, HSA and OVA are too weak to show RC. Model free analysis of the inverse intensity <span>(1/Ileft( {q to 0} right))</span> also supports this finding. Looking at different <i>q</i>-range by employing static (SLS) and dynamic light scattering experiments, the presence of RI behavior can be confirmed. The results are further discussed in view of metal cation binding sites in nucleic acids (DNA and RNA), where Hac induced RC phase behavior.</p><h3>Graphical abstract</h3>\u0000<div><figure><div><div><picture><source><img></source></picture></div></div></figure></div></div>","PeriodicalId":790,"journal":{"name":"The European Physical Journal E","volume":"46 12","pages":""},"PeriodicalIF":1.8,"publicationDate":"2023-12-05","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://link.springer.com/content/pdf/10.1140/epje/s10189-023-00376-6.pdf","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"138486370","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":4,"RegionCategory":"物理与天体物理","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"OA","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Chilling alcohol on the computer: isothermal compressibility and the formation of hydrogen-bond clusters in liquid propan-1-ol","authors":"Luis A. Baptista,&nbsp;Mauricio Sevilla,&nbsp;Manfred Wagner,&nbsp;Kurt Kremer,&nbsp;Robinson Cortes-Huerto","doi":"10.1140/epje/s10189-023-00380-w","DOIUrl":"10.1140/epje/s10189-023-00380-w","url":null,"abstract":"<p>Molecular dynamics simulations have been performed to compute the isothermal compressibility <span>(kappa _T)</span> of liquid propan-1-ol in the temperature range <span>(200 le Tle 300)</span> K. A change in behaviour, from normal (high <i>T</i>) to anomalous (low <i>T</i>), has been identified for <span>(kappa _T)</span> at <span>(210&lt;T&lt;230)</span> K. The average number of hydrogen bonds (H–bond) per molecule turns to saturation in the same temperature interval, suggesting the formation of a relatively rigid network. Indeed, simulation results show a strong tendency to form H–bond clusters with distinct boundaries, with the average largest size and width of the size distribution growing upon decreasing temperature, in agreement with previous theoretical and experimental studies. These results also emphasise a connection between the behaviour of <span>(kappa _T)</span> and the formation of nanometric structures.</p>","PeriodicalId":790,"journal":{"name":"The European Physical Journal E","volume":"46 11","pages":""},"PeriodicalIF":1.8,"publicationDate":"2023-11-29","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://www.ncbi.nlm.nih.gov/pmc/articles/PMC10687148/pdf/","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"138450677","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":4,"RegionCategory":"物理与天体物理","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"OA","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Electrostatic interactions between charge regulated spherical macroions","authors":"Hu Ruixuan,&nbsp;Arghya Majee,&nbsp;Jure Dobnikar,&nbsp;Rudolf Podgornik","doi":"10.1140/epje/s10189-023-00373-9","DOIUrl":"10.1140/epje/s10189-023-00373-9","url":null,"abstract":"<p>We study the interaction between two charge regulating spherical macroions with dielectric interior and dissociable surface groups immersed in a monovalent electrolyte solution. The charge dissociation is modelled via the Frumkin-Fowler-Guggenheim isotherm, which allows for multiple adsorption equilibrium states. The interactions are derived from the solutions of the mean-field Poisson-Boltzmann type theory with charge regulation boundary conditions. For a range of conditions we find symmetry breaking transitions from symmetric to asymmetric charge distribution exhibiting annealed charge patchiness, which results in like-charge attraction even in a univalent electrolyte—thus fundamentally modifying the nature of electrostatic interactions in charge-stabilized colloidal suspensions.</p>","PeriodicalId":790,"journal":{"name":"The European Physical Journal E","volume":"46 11","pages":""},"PeriodicalIF":1.8,"publicationDate":"2023-11-29","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"138450678","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":4,"RegionCategory":"物理与天体物理","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Surface tension between liquids containing antagonistic and regular salts","authors":"Roni Kroll,&nbsp;Moshe Gottlieb,&nbsp;Yoav Tsori","doi":"10.1140/epje/s10189-023-00378-4","DOIUrl":"10.1140/epje/s10189-023-00378-4","url":null,"abstract":"<p>We investigate theoretically the surface tension between two immiscible liquids containing antagonistic and regular salts. The mean-field model includes the electrostatic energy and the Gibbs transfer energy of the ions. We find the Donnan potential difference between the liquids and solve the Poisson–Boltzmann equation to calculate the potential and ion density profiles. When the liquids contain only a regular salt, the surface tension increases when compared to the no-salt case; in contrast, the surface tension is reduced when they contain only an antagonistic salt. When both salts are present, the surface tension can either further decrease or increase depending on the preferential solvation of the ions, in agreement with published experimental observations.</p>","PeriodicalId":790,"journal":{"name":"The European Physical Journal E","volume":"46 11","pages":""},"PeriodicalIF":1.8,"publicationDate":"2023-11-29","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"138450679","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":4,"RegionCategory":"物理与天体物理","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"MFG-E8: a model of multiple binding modes associated with ps-binding proteins","authors":"Tiffany Suwatthee,&nbsp;Daniel Kerr,&nbsp;Sofiya Maltseva,&nbsp;Charles L. Dulberger,&nbsp;Luke Hyeondo Hwang,&nbsp;Benjamin R. Slaw,&nbsp;Wei Bu,&nbsp;Binhua Lin,&nbsp;Erin J. Adams,&nbsp;Ka Yee C. Lee","doi":"10.1140/epje/s10189-023-00372-w","DOIUrl":"10.1140/epje/s10189-023-00372-w","url":null,"abstract":"<div><p>Membrane-binding proteins often associate with lipid membranes through a singular binding interface which is generally modeled as a two-state system: bound or unbound. However, even a single interface can engage with more than one mode of binding since a variety of interactions can contribute to the binding event. Unfortunately, the ability to clearly delineate the different binding modes of a singular binding interface has been elusive with existing models. Here, we present a study on milk fat globule EGF factor 8 (MFG-E8), which belongs to a class of proteins that identifies and binds phosphatidylserine (PS). These proteins detect membrane dysregulation implicated in exposed PS in apoptosis and malignant cells. In order to elucidate the factors affecting the binding of MFG-E8, we used a model system consisting of a series of lipid vesicles with varying PS mole fraction to identify the sensitivity of MFG-E8’s binding affinity to changes in electrostatics using a tryptophan fluorescence spectral shift assay. Using a newly developed model, we experimentally identified three binding modes, each associated with a different number of PS lipids, with its cooperativity for binding being enhanced by the availability of negatively charged lipids. X-ray reflectivity experiments additionally suggest that MFG-E8’s binding modes are influenced by membrane packing. The protocols established for elucidating MFG-E8’s interaction with lipid membranes under different membrane conditions can be applied to the study of other membrane-binding proteins that target specific membrane attributes, such as fluidity and electrostatics, and help elucidate these membrane targeting mechanisms and their subsequent binding events.</p><h3>Graphical abstract</h3><div><figure><div><div><picture><source><img></source></picture></div></div></figure></div></div>","PeriodicalId":790,"journal":{"name":"The European Physical Journal E","volume":"46 11","pages":""},"PeriodicalIF":1.8,"publicationDate":"2023-11-24","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"138298060","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":4,"RegionCategory":"物理与天体物理","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Drying behaviour of nanofluid sessile droplets on self-affine vis-à-vis corrugated nanorough surfaces","authors":"Deeksha Rani,&nbsp;Subhendu Sarkar","doi":"10.1140/epje/s10189-023-00374-8","DOIUrl":"10.1140/epje/s10189-023-00374-8","url":null,"abstract":"<p>In recent years, evaporative self-assembly of sessile droplets has gained considerable attention owing to its wide applicability in many areas. While the phenomenon is well studied for smooth and isotropically rough (self-affine) surfaces, investigations comparing the outcomes on self-affine vis-à-vis corrugated surfaces remains to be done. In this experimental work, we compare the wetting and evaporation dynamics of nano-colloidal microlitre droplets on self-affine and corrugated nanorough surfaces having identical roughnesses and interface properties. The coupled influence of particle size, concentration, and surface structuring has been explored. Differences in wettability and evaporation dynamics are observed, which are explained via the interaction between wetting fluid and anisotropic surface roughness. Our findings exhibit different temporal behaviour of contact radius and angle in the evaporation process of the droplets. Further, the corrugated surface exhibits anisotropic wettability with a monotonic change in droplet shape as evaporation proceeds, finally giving rise to irregular dried patterns. The scaled rim width and crack spacing of the particulate deposits are examined. Our results can inspire fabrication of surfaces that can facilitate direction-dependent droplet motion for specific applications.</p>","PeriodicalId":790,"journal":{"name":"The European Physical Journal E","volume":"46 11","pages":""},"PeriodicalIF":1.8,"publicationDate":"2023-11-24","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"138298059","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":4,"RegionCategory":"物理与天体物理","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Foam drainage equation in fractal dimensions: breaking and instabilities","authors":"Rami Ahmad El-Nabulsi,&nbsp;Waranont Anukool","doi":"10.1140/epje/s10189-023-00368-6","DOIUrl":"10.1140/epje/s10189-023-00368-6","url":null,"abstract":"<div><p>This paper is concerned with the construction of a phenomenological model for drainage of a liquid in foam in fractal dimensions. Our model is based on the concepts of “product-like fractal measure” introduced to model dynamics in porous media and “complex fractional transform” which converts a fractal space on a small scale to a smooth space with a large scale. The solution of the fractal foam drainage equation has been approximated using the He’s homotopy perturbation method. Qualitative analysis shows that the behavior of the solitonic wave in fractal dimensions differ from the behavior in integer dimensions. This deformation generates instabilities in the foam dynamics, dispersion and spontaneous breaking of the solitonic wave.</p><h3>Graphical abstract</h3>\u0000<div><figure><div><div><picture><source><img></source></picture></div></div></figure></div></div>","PeriodicalId":790,"journal":{"name":"The European Physical Journal E","volume":"46 11","pages":""},"PeriodicalIF":1.8,"publicationDate":"2023-11-13","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://link.springer.com/content/pdf/10.1140/epje/s10189-023-00368-6.pdf","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"89716584","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":4,"RegionCategory":"物理与天体物理","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"OA","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Lift at low Reynolds number","authors":"Lionel Bureau,&nbsp;Gwennou Coupier,&nbsp;Thomas Salez","doi":"10.1140/epje/s10189-023-00369-5","DOIUrl":"10.1140/epje/s10189-023-00369-5","url":null,"abstract":"<p>Lift forces are widespread in hydrodynamics. These are typically observed for big and fast objects and are often associated with a combination of fluid inertia (i.e. large Reynolds numbers) and specific symmetry-breaking mechanisms. In contrast, the properties of viscosity-dominated (i.e. low Reynolds numbers) flows make it more difficult for such lift forces to emerge. However, the inclusion of boundary effects qualitatively changes this picture. Indeed, in the context of soft and biological matter, recent studies have revealed the emergence of novel lift forces generated by boundary softness, flow gradients and/or surface charges. The aim of the present review is to gather and analyse this corpus of literature, in order to identify and unify the questioning within the associated communities, and pave the way towards future research.</p>","PeriodicalId":790,"journal":{"name":"The European Physical Journal E","volume":"46 11","pages":""},"PeriodicalIF":1.8,"publicationDate":"2023-11-13","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"92152196","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":4,"RegionCategory":"物理与天体物理","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"D11 and small angle neutron scattering: a paradigm of ILL","authors":"John White","doi":"10.1140/epje/s10189-023-00362-y","DOIUrl":"10.1140/epje/s10189-023-00362-y","url":null,"abstract":"<div><p>This paper describes some of the early events in the 50 year success of D11. That, and the Institut Laue Langevin are linked by an attitude that embraces both instrument renewal and new areas of science. The neutron sources proved to be reliable and serviceable, the neutron guides and guide hall have been a great benefit, and the user concept has led to a strengthening international community of diverse and good science and to new instruments clamouring for funding in a growing facility. Designs were perfected and the second wind (Deuxième Souffle) funded the outflow from which a second strong phase has evolved.</p><h3>Graphical Abstract</h3><div><figure><div><div><picture><source><img></source></picture></div></div></figure></div></div>","PeriodicalId":790,"journal":{"name":"The European Physical Journal E","volume":"46 11","pages":""},"PeriodicalIF":1.8,"publicationDate":"2023-11-13","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://www.ncbi.nlm.nih.gov/pmc/articles/PMC10643372/pdf/","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"92152195","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":4,"RegionCategory":"物理与天体物理","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"OA","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}