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1.
J Cell Biol ; 221(9)2022 Sep 05.
Artigo em Inglês | MEDLINE | ID: mdl-35929833

RESUMO

Membrane contact site (MCS)-mediated organelle interactions play essential roles in the cell. Quantitative analysis of MCSs reveals vital clues for cellular responses under various physiological and pathological conditions. However, an efficient tool is lacking. Here, we developed DeepContact, a deep-learning protocol for optimizing organelle segmentation and contact analysis based on label-free EM. DeepContact presents high efficiency and flexibility in interactive visualizations, accommodating new morphologies of organelles and recognizing contacts in versatile width ranges, which enables statistical analysis of various types of MCSs in multiple systems. DeepContact profiled previously unidentified coordinative rearrangements of MCS types in cultured cells with combined nutritional conditions. DeepContact also unveiled a subtle wave of ER-mitochondrial entanglement in Sertoli cells during the seminiferous epithelial cycle, indicating its potential in bridging MCS dynamics to physiological and pathological processes.


Assuntos
Retículo Endoplasmático , Mitocôndrias , Membrana Celular/metabolismo , Retículo Endoplasmático/metabolismo , Membranas/metabolismo , Microscopia Eletrônica , Mitocôndrias/metabolismo , Membranas Mitocondriais/metabolismo
2.
Proc Natl Acad Sci U S A ; 119(32): e2204453119, 2022 Aug 09.
Artigo em Inglês | MEDLINE | ID: mdl-35914159

RESUMO

Changes in the geometry and topology of self-assembled membranes underlie diverse processes across cellular biology and engineering. Similar to lipid bilayers, monolayer colloidal membranes have in-plane fluid-like dynamics and out-of-plane bending elasticity. Their open edges and micrometer-length scale provide a tractable system to study the equilibrium energetics and dynamic pathways of membrane assembly and reconfiguration. Here, we find that doping colloidal membranes with short miscible rods transforms disk-shaped membranes into saddle-shaped surfaces with complex edge structures. The saddle-shaped membranes are well approximated by Enneper's minimal surfaces. Theoretical modeling demonstrates that their formation is driven by increasing the positive Gaussian modulus, which in turn, is controlled by the fraction of short rods. Further coalescence of saddle-shaped surfaces leads to diverse topologically distinct structures, including shapes similar to catenoids, trinoids, four-noids, and higher-order structures. At long timescales, we observe the formation of a system-spanning, sponge-like phase. The unique features of colloidal membranes reveal the topological transformations that accompany coalescence pathways in real time. We enhance the functionality of these membranes by making their shape responsive to external stimuli. Our results demonstrate a pathway toward control of thin elastic sheets' shape and topology-a pathway driven by the emergent elasticity induced by compositional heterogeneity.


Assuntos
Bicamadas Lipídicas , Elasticidade , Bicamadas Lipídicas/química , Membranas/metabolismo , Distribuição Normal
3.
Curr Protoc ; 2(7): e483, 2022 Jul.
Artigo em Inglês | MEDLINE | ID: mdl-35822836

RESUMO

Membrane protein interactions are challenging to identify because of the unique biophysical characteristics of both transmembrane proteins and membrane environments. The Receptor Display in Membranes Interaction Screen (RDIMIS) platform overcomes these challenges by screening transmembrane and membrane-proximal proteins in a membrane environment using recombinant extracellular vesicles (rEVs). The screen has been used to successfully identify interactions for difficult-to-study receptors in an unbiased manner. In this report, we detail how we generate rEVs, characterize the rEVs to ensure screen-readiness, and perform the full interaction screening, with emphasis on the criteria necessary to obtain clear, interpretable results. We also include support protocols for generating a screening library and validating screening results, as well as an alternate protocol for RDIMIS enabling the profiling of naturally occurring extracellular vesicles. © 2022 Wiley Periodicals LLC. Basic Protocol 1: Generating and isolating extracellular vesicles from cells Basic Protocol 2: Characterizing recombinant extracellular vesicles Support Protocol 1: Preparing the receptor screening library Basic Protocol 3: Performing the Receptor Display in Membranes Interaction Screen (RDIMIS) Support Protocol 2: Validating RDIMIS results using microscopy Alternate Protocol: Detecting unlabeled endogenous vesicles.


Assuntos
Vesículas Extracelulares , Proteínas de Membrana , Comunicação Celular , Vesículas Extracelulares/metabolismo , Proteínas de Membrana/metabolismo , Membranas/metabolismo
4.
Sci Rep ; 12(1): 11302, 2022 Jul 04.
Artigo em Inglês | MEDLINE | ID: mdl-35787653

RESUMO

In this work demostrates a unique method for determining the absolute value of the friction force of a nanoobject on the surface of a cell membrane using atomic force microscopy. The tribological properties of membranes of adult human buccal epithelium cells in the presence of a protective adsorption buffer layer of ~ 100 nm on their surface were studied using atomic force microscopy in the contact scanning mode. Local mapping of the tribological characteristics of the surface was carried out, viz. friction FL = FL(x, y) and adhesion Fadh = Fadh(x, y) forces were measured. Studies of the friction force Ffr on the membrane surface at the nanolevel showed that its value varies discretely with an interval equal to lLF ≈ 100 nm. It was shown that such discreteness is determined by the interval lLF of the action of adhesive forces Fadh and indicates the fractal nature of the functional dependence of the friction force on the coordinate Ffr = Ffr(x). Thus, for nano-objects with dimensions ≤ lLF, the absolute value of Ffr decreases according to a power law with an increase in the size of the object, which contradicts the similar dependence of the friction force for macro-objects in the global approximation.


Assuntos
Membrana Celular , Adulto , Epitélio , Fricção , Humanos , Membranas , Microscopia de Força Atômica
5.
Int J Mol Sci ; 23(13)2022 Jun 30.
Artigo em Inglês | MEDLINE | ID: mdl-35806322

RESUMO

Small heat shock proteins (sHSPs) have been demonstrated to interact with lipids and modulate the physical state of membranes across species. Through these interactions, sHSPs contribute to the maintenance of membrane integrity. HSPB1 is a major sHSP in mammals, but its lipid interaction profile has so far been unexplored. In this study, we characterized the interaction between HSPB1 and phospholipids. HSPB1 not only associated with membranes via membrane-forming lipids, but also showed a strong affinity towards highly fluid membranes. It participated in the modulation of the physical properties of the interacting membranes by altering rotational and lateral lipid mobility. In addition, the in vivo expression of HSPB1 greatly affected the phase behavior of the plasma membrane under membrane fluidizing stress conditions. In light of our current findings, we propose a new function for HSPB1 as a membrane chaperone.


Assuntos
Proteínas de Choque Térmico Pequenas , Animais , Membrana Celular/metabolismo , Proteínas de Choque Térmico HSP27/metabolismo , Proteínas de Choque Térmico Pequenas/metabolismo , Mamíferos/metabolismo , Lipídeos de Membrana/química , Membranas/metabolismo , Fosfolipídeos
6.
Molecules ; 27(13)2022 Jun 27.
Artigo em Inglês | MEDLINE | ID: mdl-35807376

RESUMO

Ibuprofen is a non-steroidal anti-inflammatory drug possessing analgesic and antipyretic activity. Electron paramagnetic resonance (EPR) spectroscopy could be applied to study its interaction with biological membranes and proteins if its spin-labeled analogs were synthesized. Here, a simple sequence of ibuprofen transformations-nitration, esterification, reduction, Sandmeyer reaction, Sonogashira cross-coupling, oxidation and saponification-was developed to attain this goal. The synthesis resulted in spin-labeled ibuprofen (ibuprofen-SL) in which the spin label TEMPOL is attached to the benzene ring. EPR spectra confirmed interaction of ibuprofen-SL with 1-palmitoyl-2-oleoyl-sn-glycero-3-phosphocholine (POPC) bilayers. Using 2H electron spin echo envelope modulation (ESEEM) spectroscopy, ibuprofen-SL was found to be embedded into the hydrophobic bilayer interior.


Assuntos
Ibuprofeno , Bicamadas Lipídicas , Espectroscopia de Ressonância de Spin Eletrônica , Bicamadas Lipídicas/química , Membranas , Marcadores de Spin
7.
Methods Mol Biol ; 2473: 259-284, 2022.
Artigo em Inglês | MEDLINE | ID: mdl-35819771

RESUMO

Light scattering methods permit the determination of molar mass and hydrodynamic radius for a protein from first principles. They are, therefore, particularly useful for the biophysical characterization of any protein. Molar mass and hydrodynamic radius determinations may be used to demonstrate that the protein of interest multimerizes. In the endomembrane system, reversible and regulated assembly and multimerization of proteins is critical for building coats required for vesicle budding, for the function of membrane remodeling machines, for fission and fusion and for assembling and disassembling trafficking intermediates. Light scattering methods have therefore significantly contributed to the understanding of the underlying trafficking processes. Herein, we describe methods to express and purify the recombinant fungal SNX-BAR Mvp1, a membrane remodeling protein required for retrograde trafficking at the endosome. Using Mvp1 as an example, we provide protocols for determining its molar mass and hydrodynamic radius by multiangle static light scattering and dynamic light scattering, respectively. These methods can be applied directly to the study of other membrane trafficking proteins, yielding a wealth of biophysical and biochemical information.


Assuntos
Hidrodinâmica , Proteínas , Endossomos , Membranas , Peso Molecular
8.
Methods Mol Biol ; 2473: 309-331, 2022.
Artigo em Inglês | MEDLINE | ID: mdl-35819773

RESUMO

Intracellular membrane trafficking is a dynamic and complex cellular process. To study membrane trafficking with a high spatiotemporal resolution, we present an optogenetic method based on a blue-light inducible oligomerization of Rab GTPases, termed light-activated reversible inhibition by assembly trap of intracellular membranes (IM-LARIAT). In this chapter, we focus on the optical disruption of the dynamics and functions of previously studied intracellular membrane trafficking events, including transferrin recycling and growth cone regulation in relation to specific Rab GTPases. To aid general application, we provide a detailed description of transfection, imaging with a confocal microscope, and analysis of data.


Assuntos
Membranas Intracelulares , Optogenética , Cones de Crescimento/metabolismo , Membranas Intracelulares/metabolismo , Membranas/metabolismo , Optogenética/métodos , Proteínas rab de Ligação ao GTP/genética , Proteínas rab de Ligação ao GTP/metabolismo
9.
Int J Mol Sci ; 23(13)2022 Jun 27.
Artigo em Inglês | MEDLINE | ID: mdl-35806152

RESUMO

Two non-commercial metallic Au-based complexes were tested against one of the most aggressive malignant melanomas of the skin (MeWo cells), through cell viability and time-lapse live-cell imaging system assays. The tests with the complexes were carried out both in the form of free metallic complexes, directly in contact with the MeWo cell line culture, and embedded in fibers of Polycaprolactone (PCL) membranes produced by the electrospinning technique. Membranes functionalized with complexes were prepared to evaluate the efficiency of the membranes against the melanoma cells and therefore their feasibility in the application as an antitumoral patch for topical use. Both series of tests highlighted a very effective antitumoral activity, manifesting a very relevant cell viability inhibition after both 24 h and 48 h. In the case of the AuM1 complex at the concentration of 20 mM, melanoma cells completely died in this short period of time. A mortality of around 70% was detected from the tests performed using the membranes functionalized with AuM1 complex at a very low concentration (3 wt.%), even after 24 h of the contact period. The synthesized complexes also manifest high selectivity with respect to the MeWo cells. The peculiar structural and morphological organization of the nanofibers constituting the membranes allows for a very effective antitumoral activity in the first 3 h of treatment. Experimental points of the release profiles were perfectly fitted with theoretical curves, which easily allow interpretation of the kinetic phenomena occurring in the release of the synthesized complexes in the chosen medium.


Assuntos
Melanoma , Nanofibras , Apoptose , Ouro/farmacologia , Humanos , Membranas , Nanofibras/química , Poliésteres/química
10.
Langmuir ; 38(31): 9649-9659, 2022 Aug 09.
Artigo em Inglês | MEDLINE | ID: mdl-35878409

RESUMO

Curcumin, the main ingredient in turmeric, has attracted attention due to its potential anti-inflammatory, anticancer, wound-healing, and antioxidant properties. Though curcumin efficacy is related to its interaction with biomembranes, there are few reports on the effects of curcumin on the lateral motion of lipids, a fundamental process in the cell membrane. Employing the quasielastic neutron scattering technique, we explore the effects of curcumin on the lateral diffusion of the dipalmotylphosphatidylcholine (DPPC) membrane. Our investigation is also supported by Fourier transform infrared spectroscopy, dynamic light scattering, and calorimetry to understand the interaction between curcumin and the DPPC membrane. It is found that curcumin significantly modulates the packing arrangement and conformations of DPPC lipid, leading to enhanced membrane dynamics. In particular, we find that the presence of curcumin substantially accelerates the DPPC lateral motion in both ordered and fluid phases. The effects are more pronounced in the ordered phase where the lateral diffusion coefficient increases by 23% in comparison to 9% in the fluid phase. Our measurements provide critical insights into molecular mechanisms underlying increased lateral diffusion. In contrast, the localized internal motions of DPPC are barely altered, except for a marginal enhancement observed in the ordered phase. In essence, these findings indicate that curcumin is favorably located at the membrane interface rather than in a transbilayer configuration. Further, the unambiguous evidence that curcumin modulates the membrane dynamics at a molecular level supports a possible action mechanism in which curcumin can act as an allosteric regulator of membrane functionality.


Assuntos
Curcumina , Bicamadas Lipídicas , 1,2-Dipalmitoilfosfatidilcolina/química , Membrana Celular/química , Curcumina/química , Bicamadas Lipídicas/química , Membranas , Movimento (Física)
11.
Anal Chem ; 94(31): 11089-11095, 2022 Aug 09.
Artigo em Inglês | MEDLINE | ID: mdl-35900192

RESUMO

Cancer is a health threat worldwide, and it is urgent to develop more sensitive cancer detection methods. Herein, a polarity-sensitive cell membrane probe (named COP) was developed for detecting cancer cells and tumors sensitively and selectively at the cell membrane level. The probe shows a strong polarity-dependent fluorescence and excellent cell membrane targeting ability to visualize cell membrane with red fluorescence with a non-washing process. Notably, COP can selectively light up the tumor cell membranes, which reveals that cancer cell membranes have lower polarity than normal cell membranes. The giant unilamellar vesicle model and cell imaging studies proved this. Moreover, COP can effectively and selectively light up tumors. Overall, this work demonstrates that the polarity of the tumor cell membrane is quite different to normal cell membranes, and based on this, sensitive membrane probes can be developed to selectively visualize cancer cells and tumors, which opens up a new way for tumor diagnosis at the cellular level.


Assuntos
Corantes Fluorescentes , Membrana Celular/metabolismo , Corantes Fluorescentes/metabolismo , Membranas/metabolismo , Espectrometria de Fluorescência
12.
Int J Mol Sci ; 23(15)2022 Jul 22.
Artigo em Inglês | MEDLINE | ID: mdl-35897670

RESUMO

Eukaryotic cells contain membranes with various curvatures, from the near-plane plasma membrane to the highly curved membranes of organelles, vesicles, and membrane protrusions. These curvatures are generated and sustained by curvature-inducing proteins, peptides, and lipids, and describing these mechanisms is an important scientific challenge. In addition to that, some molecules can sense membrane curvature and thereby be trafficked to specific locations. The description of curvature sensing is another fundamental challenge. Curved lipid membranes and their interplay with membrane-associated proteins can be investigated with molecular dynamics (MD) simulations. Various methods for simulating curved membranes with MD are discussed here, including tools for setting up simulation of vesicles and methods for sustaining membrane curvature. The latter are divided into methods that exploit scaffolding virtual beads, methods that use curvature-inducing molecules, and methods applying virtual forces. The variety of simulation tools allow researcher to closely match the conditions of experimental studies of membrane curvatures.


Assuntos
Bicamadas Lipídicas , Simulação de Dinâmica Molecular , Membrana Celular/metabolismo , Bicamadas Lipídicas/química , Membranas/metabolismo , Proteínas/análise
13.
Int J Mol Sci ; 23(15)2022 Jul 24.
Artigo em Inglês | MEDLINE | ID: mdl-35897726

RESUMO

Our objective was to determine and optimize the significant parameters affecting mechanical properties and mean fiber diameter (MFD) of a novel GTR/GBR membrane composed of polycaprolactone (PCL) and chicken eggshell membrane (ESM). For this, we prepared electrospun membrane specimens (n = 16) with varying concentrations of PCL, ESM, nano-hydroxyapatite (HAp), and altered electrospinning parameters as generated by DOE++ software. After the determination of MFD and mechanical properties for all specimens, Taguchi orthogonal array L8 design was used to screen significant factors affecting the MFD and mechanical properties. PCL wt%, ESM wt%, HAp wt%, applied voltage (AV), flow rate (FR), and spinneret-collector distance (SCD) were the independent variables investigated. The response variables analyzed were MFD, tensile strength (TS), and elastic modulus. ANOVA outlined ESM wt%, HAp wt%, AV, FR, SCD, and an interactive effect between PCL wt% and AV to be the significant factors affecting modulus values of an electrospun PCL/ESM membrane (p < 0.05). Furthermore, concentrations of PCL and ESM were the significant factors affecting MFD (p < 0.05) and there were no significant factors affecting the TS values. Optimization using DOE++ software predicted that the maximal TS of 3.125 MPa, modulus of 278.168 MPa, and MFD of 882.75 nm could be achieved.


Assuntos
Nanofibras , Durapatita , Membranas , Poliésteres
14.
Int J Mol Sci ; 23(14)2022 Jul 09.
Artigo em Inglês | MEDLINE | ID: mdl-35886964

RESUMO

Liposomes and planar membranes made of archaea or archaea-like lipids exhibit many unusual physical properties compared to model membranes composed of conventional diester lipids. Here, we review several recent findings in this research area, which include (1) thermosensitive archaeosomes with the capability to drastically change the membrane surface charge, (2) MthK channel's capability to insert into tightly packed tetraether black lipid membranes and exhibit channel activity with surprisingly high calcium sensitivity, and (3) the intercalation of apolar squalane into the midplane space of diether bilayers to impede proton permeation. We also review the usage of tetraether archaeosomes as nanocarriers of therapeutics and vaccine adjuvants, as well as the biomedical applications of planar archaea lipid membranes. The discussion on archaeosomal therapeutics is focused on partially purified tetraether lipid fractions such as the polar lipid fraction E (PLFE) and glyceryl caldityl tetraether (GCTE), which are the main components of PLFE with the sugar and phosphate removed.


Assuntos
Archaea , Lipossomos , Lipídeos , Membranas , Prótons
15.
Int J Mol Sci ; 23(14)2022 Jul 19.
Artigo em Inglês | MEDLINE | ID: mdl-35887303

RESUMO

Present research was directed towards the development of new high-performance and cost-effective polysulfone membranes (PSFQ) by introducing ionic liquids (ILs-Cyphos 101 IL and Aliquat 336) into their matrix. Variation of ILs was performed with the aim to find the one that brings new properties and improves the functionality and selectivity of PSFQ membranes in ultrafiltration processes. Based on the obtained results of the rheological study, we established the compatibility of compounds and optimal content of the used ILs, namely 3 wt% and 15 wt% Cyphos 101 IL and compositions varying between 3 and 15 wt % Aliquat 336. Results indicated that the ILs acted as plasticizers when they were added to the system, a helpful aspect in processing membranes used in water decontamination. The efficiency and performance of the membranes were evaluated by their use in the treatment of diclofenac (DCF)-containing waters. Membranes obtained from PSFQ/Aliquat 336 solution containing 15 wt% IL exhibited a 97% removal degree of DCF in the treatment process of 50 mL solution containing 3 mg/L DCF. The separation efficiency was kept constant for four filtration/cleaning cycles. The results indicated an improvement in membrane performance as the amount of IL in their structure increased, which confirms the potential for application in water treatment processes.


Assuntos
Líquidos Iônicos , Líquidos Iônicos/química , Membranas , Membranas Artificiais
16.
J Chem Phys ; 157(3): 034901, 2022 Jul 21.
Artigo em Inglês | MEDLINE | ID: mdl-35868922

RESUMO

Curvature-inducing proteins containing a bin/amphiphysin/Rvs domain often have intrinsically disordered domains. Recent experiments have shown that these disordered chains enhance curvature sensing and generation. Here, we report on the modification of protein-membrane interactions by disordered chains using meshless membrane simulations. The protein and bound membrane are modeled together as a chiral crescent protein rod with two excluded-volume chains. As the chain length increases, the repulsion between them reduces the cluster size of the proteins. It induces spindle-shaped vesicles and a transition between arc-shaped and circular protein assemblies in a disk-shaped vesicle. For flat membranes, an intermediate chain length induces many tubules owing to the repulsion between the protein assemblies, whereas longer chains promote perpendicular elongation of tubules. Moreover, protein rods with zero rod curvature and sufficiently long chains stabilize the spherical buds. For proteins with a negative rod curvature, an intermediate chain length induces a rugged membrane with branched protein assemblies, whereas longer chains induce the formation of tubules with periodic concave-ring structures.


Assuntos
Membrana Celular , Membrana Celular/química , Membranas
17.
Sci Rep ; 12(1): 12170, 2022 Jul 16.
Artigo em Inglês | MEDLINE | ID: mdl-35842540

RESUMO

Membrane technology with advantages such as reduced energy consumption due to no phase change, low volume and high mass transfer, high separation efficiency for solution solutions, straightforward design of membranes, and ease of use on industrial scales are different from other separation methods. There are various methods such as liquid-liquid extraction, adsorption, precipitation, and membrane processes to separate contaminants from an aqueous solution. The liquid membrane technique provides a practical and straightforward separation method for metal ions as an advanced solvent extraction technique. Stabilized liquid membranes require less solvent consumption, lower cost, and more effortless mass transfer due to their thinner thickness than other liquid membrane techniques. The influence of the electrostatic properties, derived from the electrical field, on the ionic transport rate and extraction recovery, in flat sheet supported liquid membrane (FSLM) and electro flat sheet supported liquid membrane (EFSLM) were numerically investigated. Both FSLM and EFSLM modes of operation, in terms of implementing electrostatic, were considered. Through adopting a numerical approach, Poisson-Nernst-Planck, and Navier-Stokes equations were solved at unsteady-state conditions by considering different values of permittivity, diffusivity, and viscosity for the presence of electrical force and stirrer, respectively. The most important result of this study is that under similar conditions, by increasing the applied voltage, the extraction recovery increased. For instance, at EFSLM mode, by increasing the applied voltage from [Formula: see text] to [Formula: see text], the extraction recovery increased from [Formula: see text] to [Formula: see text]. Furthermore, it was also observed that the presence of nanoparticles has significant effects on the performance of the SLM system.


Assuntos
Eletricidade Estática , Simulação por Computador , Transporte de Íons , Membranas , Solventes
18.
Small ; 18(31): e2201473, 2022 Aug.
Artigo em Inglês | MEDLINE | ID: mdl-35808958

RESUMO

The control of heat at the nanoscale via the excitation of localized surface plasmons in nanoparticles (NPs) irradiated with light holds great potential in several fields (cancer therapy, catalysis, desalination). To date, most thermoplasmonic applications are based on Ag and Au NPs, whose cost of raw materials inevitably limits the scalability for industrial applications requiring large amounts of photothermal NPs, as in the case of desalination plants. On the other hand, alternative nanomaterials proposed so far exhibit severe restrictions associated with the insufficient photothermal efficacy in the visible, the poor chemical stability, and the challenging scalability. Here, it is demonstrated the outstanding potential of NiSe and CoSe topological nodal-line semimetals for thermoplasmonics. The anisotropic dielectric properties of NiSe and CoSe activate additional plasmonic resonances. Specifically, NiSe and CoSe NPs support multiple localized surface plasmons in the optical range, resulting in a broadband matching with sunlight radiation spectrum. Finally, it is validated the proposed NiSe and CoSe-based thermoplasmonic platform by implementing solar-driven membrane distillation by adopting NiSe and CoSe nanofillers embedded in a polymeric membrane for seawater desalination. Remarkably, replacing Ag with NiSe and CoSe for solar membrane distillation increases the transmembrane flux by 330% and 690%, respectively. Correspondingly, costs of raw materials are also reduced by 24 and 11 times, respectively. The results pave the way for the advent of NiSe and CoSe for efficient and sustainable thermoplasmonics and related applications exploiting sunlight within the paradigm of the circular blue economy.


Assuntos
Energia Solar , Purificação da Água , Destilação/métodos , Membranas , Luz Solar , Purificação da Água/métodos
19.
Phys Chem Chem Phys ; 24(30): 18133-18143, 2022 Aug 03.
Artigo em Inglês | MEDLINE | ID: mdl-35856570

RESUMO

Recent experimental studies revealed that functional membrane microdomains (FMMs) are formed in prokaryotic cells which are structurally and functionally similar to the lipid rafts formed in eukaryotic cells. In this study, we employ coarse-grained molecular dynamics simulations to investigate the mechanism of domain formation and its physiochemical properties in a model methicillin-resistant staphylococcus aureus (MRSA) cell membrane. We find that domains are formed through lateral segregation of staphyloxanthin (STX), a carotenoid which shields the bacteria from the host's immune because of its antioxidant nature. Simulation results suggest that membrane integrity increases with the size of the domain, which is assessed by computing bond order parameter of the lipid tails, membrane expansion modulus and water permeability across the membrane. Various membrane domain proteins such as flotillin-like protein floA and penicillin binding protein (PBP2a) preferentially bind with the STX and accumulate in the membrane domain which is consistent with the recent experimental results.


Assuntos
Staphylococcus aureus Resistente à Meticilina , Antibacterianos/metabolismo , Proteínas de Bactérias/metabolismo , Membrana Celular/metabolismo , Microdomínios da Membrana/química , Microdomínios da Membrana/metabolismo , Membranas , Staphylococcus aureus Resistente à Meticilina/metabolismo
20.
Biomolecules ; 12(6)2022 05 29.
Artigo em Inglês | MEDLINE | ID: mdl-35740882

RESUMO

The peritoneal membrane is the largest internal membrane of the human body, having a surface area that approximates the surface area of the skin [...].


Assuntos
Diálise Peritoneal , Humanos , Membranas , Peritônio , Pele
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