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1.
Nat Commun ; 15(1): 3767, 2024 May 04.
Article in English | MEDLINE | ID: mdl-38704407

ABSTRACT

Tools for accessing and studying organelles remain underdeveloped. Here, we present a method by which giant organelle vesicles (GOVs) are generated by submitting cells to a hypotonic medium followed by plasma membrane breakage. By this means, GOVs ranging from 3 to over 10 µm become available for micromanipulation. GOVs are made from organelles such as the endoplasmic reticulum, endosomes, lysosomes and mitochondria, or in contact with one another such as giant mitochondria-associated ER membrane vesicles. We measure the mechanical properties of each organelle-derived GOV and find that they have distinct properties. In GOVs procured from Cos7 cells, for example, bending rigidities tend to increase from the endoplasmic reticulum to the plasma membrane. We also found that the mechanical properties of giant endoplasmic reticulum vesicles (GERVs) vary depending on their interactions with other organelles or the metabolic state of the cell. Lastly, we demonstrate GERVs' biochemical activity through their capacity to synthesize triglycerides and assemble lipid droplets. These findings underscore the potential of GOVs as valuable tools for studying the biophysics and biology of organelles.


Subject(s)
Endoplasmic Reticulum , Intracellular Membranes , Animals , Chlorocebus aethiops , COS Cells , Endoplasmic Reticulum/metabolism , Intracellular Membranes/metabolism , Cell Membrane/metabolism , Mitochondria/metabolism , Organelles/metabolism , Lipid Droplets/metabolism , Triglycerides/metabolism , Humans , Lysosomes/metabolism
2.
Arch Microbiol ; 206(6): 251, 2024 May 10.
Article in English | MEDLINE | ID: mdl-38727840

ABSTRACT

The prevalence of Candida albicans infection has increased during the past few years, which contributes to the need for new, effective treatments due to the increasing concerns regarding antifungal drug toxicity and multidrug resistance. Butyl isothiocyanate (butylITC) is a glucosinolate derivative, and has shown a significant antifungal effect contrary to Candida albicans. Additionally, how butylITC affects the virulence traits of C. albicans and molecular mode of actions are not well known. Present study shows that at 17.36 mM concentration butylITC inhibit planktonic growth. butylITC initially slowed the hyphal transition at 0.542 mM concentration. butylITC hampered biofilm development, and inhibits biofilm formation at 17.36 mM concentration which was analysed using metabolic assay (XTT assay) and Scanning Electron Microscopy (SEM). In addition, it was noted that butylITC inhibits ergosterol biosynthesis. The permeability of cell membranes was enhanced by butylITC treatment. Moreover, butylITC arrests cells at S-phase and induces intracellular Reactive Oxygen Species (ROS) accumulation in C. albicans. The results suggest that butylITC may have a dual mode of action, inhibit virulence factors and modulate cellular processes like inhibit ergosterol biosynthesis, cell cycle arrest, induces ROS production which leads to cell death in C. albicans.


Subject(s)
Antifungal Agents , Biofilms , Candida albicans , Cell Membrane , Isothiocyanates , Oxidative Stress , Reactive Oxygen Species , Candida albicans/drug effects , Candida albicans/physiology , Biofilms/drug effects , Antifungal Agents/pharmacology , Isothiocyanates/pharmacology , Oxidative Stress/drug effects , Cell Membrane/drug effects , Cell Membrane/metabolism , Reactive Oxygen Species/metabolism , Microbial Sensitivity Tests , Cell Cycle/drug effects , Hyphae/drug effects , Hyphae/growth & development , Ergosterol/metabolism
3.
Methods Mol Biol ; 2799: 55-77, 2024.
Article in English | MEDLINE | ID: mdl-38727903

ABSTRACT

NMDA-type ionotropic glutamate receptors are critically involved in many brain functions and are implicated in a variety of brain disorders. Seven NMDA receptor subunits exist (GluN1, GluN2A-D, and GluN3A-B) that assemble into tetrameric receptor subtypes with distinct functional properties and physiological roles. The majority NMDA receptors are composed of two GluN1 and two GluN2 subunits, which can assemble into four diheteromeric receptors subtypes composed of GluN1 and one type of GluN2 subunit (e.g., GluN1/2A), and presumably also six triheteromeric receptor subtypes composed of GluN1 and two different GluN2 subunits (e.g., GluN1/2A/2B). Furthermore, the GluN1 subunit exists as eight splice variants (e.g., GluN1-1a and GluN1-1b isoforms), and two different GluN1 isoforms can co-assemble to also form triheteromeric NMDA receptors (e.g., GluN1-1a/1b/2A). Here, we describe a method to faithfully express triheteromeric NMDA receptors in heterologous expression systems by controlling the identity of two of the four subunits. This method overcomes the problem that co-expression of three different NMDA receptor subunits generates two distinct diheteromeric receptor subtypes as well as one triheteromeric receptor subtype, thereby confounding studies that require a homogenous population of triheteromeric NMDA receptors. The method has been applied to selectively express recombinant triheteromeric GluN1/2A/2B, GluN1/2A/2C, GluN1/2B/2D, GluN1-1a/GluN1-1b/2A, GluN1-1a/GluN1-1b/2B receptors with negligible co-expression of the respective diheteromeric receptor subtypes. This method therefore enables quantitative evaluation of functional and pharmacological properties of triheteromeric NMDA receptors, some of which are abundant NMDA receptor subtypes in the adult brain.


Subject(s)
Protein Isoforms , Protein Subunits , Receptors, N-Methyl-D-Aspartate , Receptors, N-Methyl-D-Aspartate/metabolism , Receptors, N-Methyl-D-Aspartate/genetics , Humans , Protein Subunits/metabolism , Protein Subunits/genetics , Protein Isoforms/genetics , Protein Isoforms/metabolism , HEK293 Cells , Animals , Cell Membrane/metabolism , Gene Expression
4.
Curr Protoc ; 4(5): e1045, 2024 May.
Article in English | MEDLINE | ID: mdl-38717451

ABSTRACT

The cell surface distribution patterns (clustering) of membrane proteins have been widely investigated in cell biology. Here we describe a novel transmission electron microscopic (TEM) protocol designed to improve the quality of information obtained about the protein distribution patterns detected. This novel method makes it possible to study the clustering of all transmembrane proteins on one half of the cytoplasmic membrane of a whole cell. To achieve better imaging, we combine various methods, including critical-point drying, fixation of gold beads with a carbon layer, and a newly developed chemical thinning method. In addition, in our image-processing algorithm, we implemented pair correlation and pair cross-correlation functions, providing more details and better quantitative accuracy in characterizing the size and numbers of possible protein clusters. © 2024 The Authors. Current Protocols published by Wiley Periodicals LLC. Basic Protocol 1: Sample preparation and transmission electron micrography Alternate Protocol: Direct cell labeling for transmission electron micrography Basic Protocol 2: Analysis of TEM images to detect immunogold-labeled proteins.


Subject(s)
Cell Membrane , Membrane Proteins , Microscopy, Electron, Transmission , Microscopy, Electron, Transmission/methods , Membrane Proteins/metabolism , Membrane Proteins/ultrastructure , Cell Membrane/metabolism , Cell Membrane/ultrastructure , Image Processing, Computer-Assisted/methods , Humans , Algorithms
5.
Sci Rep ; 14(1): 10561, 2024 05 08.
Article in English | MEDLINE | ID: mdl-38719884

ABSTRACT

This study focuses on understanding the structural and molecular changes in lipid membranes under the influence of six halogenated flavonoid derivatives differing in the number and position of substitution of chlorine and bromine atoms (D1-D6). Utilizing various analytical techniques, including fluorometric methods, dynamic light scattering (DLS), attenuated Fourier transform infrared spectroscopy (ATR- FTIR), and FT-Raman spectroscopy, the research aims to elucidate the mechanisms underlying the interaction of flavonoids with cell membranes. Additionally, the study includes in silico analyses to explore the physicochemical properties of these compounds and their potential pharmaceutical applications, along with toxicity studies to assess their effects on cancer, normal, and red blood cells. Our study showed the ability of halogenated derivatives to interact mostly with the outer part of the membrane, especially in the lipid heads region however, some of them were able to penetrate deeper into the membrane and affect the fluidity of hydrocarbon chains. The potential to reduce cancer cell viability, the lack of toxicity towards erythrocytes, and the favourable physicochemical and pharmacokinetic properties suggest these halogenated flavonoids potential candidates for exploring their potential for medical use.


Subject(s)
Flavonoids , Membrane Lipids , Flavonoids/chemistry , Flavonoids/pharmacology , Flavonoids/metabolism , Humans , Membrane Lipids/metabolism , Membrane Lipids/chemistry , Cell Membrane/metabolism , Halogenation , Cytotoxins/chemistry , Cytotoxins/pharmacology , Cytotoxins/metabolism , Erythrocytes/drug effects , Erythrocytes/metabolism , Cell Survival/drug effects , Spectrum Analysis, Raman , Spectroscopy, Fourier Transform Infrared , Antineoplastic Agents/pharmacology , Antineoplastic Agents/chemistry , Antineoplastic Agents/metabolism , Cell Line, Tumor
6.
Eur Phys J E Soft Matter ; 47(5): 30, 2024 May 08.
Article in English | MEDLINE | ID: mdl-38720027

ABSTRACT

The aggregation or clustering of proteins and other macromolecules plays an important role in the formation of large-scale molecular assemblies within cell membranes. Examples of such assemblies include lipid rafts, and postsynaptic domains (PSDs) at excitatory and inhibitory synapses in neurons. PSDs are rich in scaffolding proteins that can transiently trap transmembrane neurotransmitter receptors, thus localizing them at specific spatial positions. Hence, PSDs play a key role in determining the strength of synaptic connections and their regulation during learning and memory. Recently, a two-dimensional (2D) diffusion-mediated aggregation model of PSD formation has been developed in which the spatial locations of the clusters are determined by a set of fixed anchoring sites. The system is kept out of equilibrium by the recycling of particles between the cell membrane and interior. This results in a stationary distribution consisting of multiple clusters, whose average size can be determined using an effective mean-field description of the particle concentration around each anchored cluster. In this paper, we derive corrections to the mean-field approximation by applying the theory of diffusion in singularly perturbed domains. The latter is a powerful analytical method for solving two-dimensional (2D) and three-dimensional (3D) diffusion problems in domains where small holes or perforations have been removed from the interior. Applications range from modeling intracellular diffusion, where interior holes could represent subcellular structures such as organelles or biological condensates, to tracking the spread of chemical pollutants or heat from localized sources. In this paper, we take the bounded domain to be the cell membrane and the holes to represent anchored clusters. The analysis proceeds by partitioning the membrane into a set of inner regions around each cluster, and an outer region where mean-field interactions occur. Asymptotically matching the inner and outer stationary solutions generates an asymptotic expansion of the particle concentration, which includes higher-order corrections to mean-field theory that depend on the positions of the clusters and the boundary of the domain. Motivated by a recent study of light-activated protein oligomerization in cells, we also develop the analogous theory for cluster formation in a three-dimensional (3D) domain. The details of the asymptotic analysis differ from the 2D case due to the contrasting singularity structure of 2D and 3D Green's functions.


Subject(s)
Cell Membrane , Diffusion , Cell Membrane/metabolism , Cell Membrane/chemistry , Membrane Microdomains/chemistry , Membrane Microdomains/metabolism , Models, Biological
7.
J Nanobiotechnology ; 22(1): 231, 2024 May 08.
Article in English | MEDLINE | ID: mdl-38720360

ABSTRACT

BACKGROUND: Circulating tumor cells (CTCs) are considered as a useful biomarker for early cancer diagnosis, which play a crucial role in metastatic process. Unfortunately, the tumor heterogeneity and extremely rare occurrence rate of CTCs among billions of interfering leukocytes seriously hamper the sensitivity and purity of CTCs isolation. METHODS: To address these, we firstly used microfluidic chips to detect the broad-spectrum of triple target combination biomarkers in CTCs of 10 types of cancer patients, including EpCAM, EGFR and Her2. Then, we constructed hybrid engineered cell membrane-camouflaged magnetic nanoparticles (HE-CM-MNs) for efficient capture of heterogeneous CTCs with high-purity, which was enabled by inheriting the recognition ability of HE-CM for various CTCs and reducing homologous cell interaction with leukocytes. Compared with single E-CM-MNs, HE-CM-MNs showed a significant improvement in the capture efficiency for a cell mixture, with an efficiency of 90%. And the capture efficiency of HE-CM-MNs toward 12 subpopulations of tumor cells was ranged from 70 to 85%. Furthermore, by using HE-CM-MNs, we successfully isolated heterogeneous CTCs with high purity from clinical blood samples. Finally, the captured CTCs by HE-CM-MNs could be used for gene mutation analysis. CONCLUSIONS: This study demonstrated the promising potential of HE-CM-MNs for heterogeneous CTCs detection and downstream analysis.


Subject(s)
Biomarkers, Tumor , Cell Membrane , Cell Separation , Magnetite Nanoparticles , Neoplastic Cells, Circulating , Neoplastic Cells, Circulating/pathology , Neoplastic Cells, Circulating/metabolism , Humans , Magnetite Nanoparticles/chemistry , Cell Separation/methods , Cell Line, Tumor , Cell Membrane/metabolism , Cell Membrane/chemistry , Biomarkers, Tumor/blood , Receptor, ErbB-2 , Epithelial Cell Adhesion Molecule/metabolism , ErbB Receptors/genetics , ErbB Receptors/metabolism , Neoplasms
8.
J Phys Chem B ; 128(18): 4414-4427, 2024 May 09.
Article in English | MEDLINE | ID: mdl-38690887

ABSTRACT

This study elucidated the mechanism of formation of a tripartite complex containing daptomycin (Dap), lipid II, and phospholipid phosphatidylglycerol in the bacterial septum membrane, which was previously reported as the cause of the antibacterial action of Dap against gram-positive bacteria via molecular dynamics and enhanced sampling methods. Others have suggested that this transient complex ushers in the inhibition of cell wall synthesis by obstructing the downstream polymerization and cross-linking processes involving lipid II, which is absent in the presence of cardiolipin lipid in the membrane. In this work, we observed that the complex was stabilized by Ca2+-mediated electrostatic interactions between Dap and lipid head groups, hydrophobic interaction, hydrogen bonds, and salt bridges between the lipopeptide and lipids and was associated with Dap concentration-dependent membrane depolarization, thinning of the bilayer, and increased lipid tail disorder. Residues Orn6 and Kyn13, along with the DXDG motif, made simultaneous contact with constituent lipids, hence playing a crucial role in the formation of the complex. Incorporating cardiolipin into the membrane model led to its competitively displacing lipid II away from the Dap, reducing the lifetime of the complex and the nonexistence of lipid tail disorder and membrane depolarization. No evidence of water permeation inside the membrane hydrophobic interior was noted in all of the systems studied. Additionally, it was shown that using hydrophobic contacts between Dap and lipids as collective variables for enhanced sampling gave rise to a free energy barrier for the translocation of the lipopeptide. A better understanding of Dap's antibacterial mechanism, as studied through this work, will help develop lipopeptide-based antibiotics for rising Dap-resistant bacteria.


Subject(s)
Anti-Bacterial Agents , Daptomycin , Molecular Dynamics Simulation , Phospholipids , Daptomycin/pharmacology , Daptomycin/chemistry , Anti-Bacterial Agents/pharmacology , Anti-Bacterial Agents/chemistry , Phospholipids/chemistry , Phospholipids/metabolism , Uridine Diphosphate N-Acetylmuramic Acid/analogs & derivatives , Uridine Diphosphate N-Acetylmuramic Acid/metabolism , Uridine Diphosphate N-Acetylmuramic Acid/chemistry , Cell Membrane/drug effects , Cell Membrane/metabolism , Phosphatidylglycerols/chemistry , Hydrophobic and Hydrophilic Interactions , Cardiolipins/chemistry , Cardiolipins/metabolism
9.
J Phys Chem B ; 128(18): 4456-4463, 2024 May 09.
Article in English | MEDLINE | ID: mdl-38691101

ABSTRACT

Ionic liquids (ILs) have shown promising potential in membrane protein extraction; however, the underlying mechanism remains unclear. Herein, we employed GPU-accelerated molecular dynamics (MD) simulations to investigate the dynamic insertion process of ILs into cell membranes containing membrane proteins. Our findings reveal that ILs spontaneously insert into the membrane, and the presence of membrane proteins significantly decelerates the rate of IL insertion into the membrane. Specifically, the relationship between the insertion rate and inserting free energy exhibits non-monotonic changes, which can be attributed to interfacial effects. The protein-water interface acts as trap for free ions and ionic clusters, while free ions preferentially insert into the membrane from the protein-lipid interface, which limits the insertion rate due to its narrowness. Thus, the insertion rate is governed by a combination of the free energy and interfacial effects. These findings provide valuable insights into the interfacial effects of protein-lipid bilayers and have implications for various biochemical-related applications.


Subject(s)
Cell Membrane , Imidazoles , Ionic Liquids , Lipid Bilayers , Molecular Dynamics Simulation , Ionic Liquids/chemistry , Imidazoles/chemistry , Cell Membrane/chemistry , Cell Membrane/metabolism , Lipid Bilayers/chemistry , Lipid Bilayers/metabolism , Membrane Proteins/chemistry , Membrane Proteins/metabolism , Thermodynamics , Water/chemistry
10.
Med Sci Monit ; 30: e942946, 2024 May 03.
Article in English | MEDLINE | ID: mdl-38698627

ABSTRACT

BACKGROUND Cryopreservation preserves male fertility, crucial in oncology, advanced age, and infertility. However, it damages sperm motility, membrane, and DNA. Zinc (Zn), an antioxidant, shows promise in improving sperm quality after thawing, highlighting its potential as a cryoprotectant in reproductive medicine. MATERIAL AND METHODS Gradient concentration of ZnSO4 (0, 12.5, 25, 50, and 100 µM) was added in the Glycerol-egg yolk-citrate (GEYC) cryopreservative medium as an extender. Alterations in sperm viability and motility parameters after cryopreservation were detected in each group. Sperm plasma membrane integrity (PMI), acrosome integrity (ACR), DNA fragment index (DFI), and changes in sperm mitochondrial function were examined, including: mitochondrial potential (MMP), sperm reactive oxygen species (ROS), and sperm ATP. RESULTS We found that 50 µM ZnSO4 was the most effective for the curvilinear velocity (VCL) and the average path velocity (VAP) of sperm after cryo-resuscitation. Compared to the Zn-free group, sperm plasma membrane integrity (PMI) was increased, DNA fragmentation index (DFI) was decreased, reactive oxygen species (ROS) was reduced, and mitochondrial membrane potential (MMP) was increased after cryorevival in the presence of 50 µM ZnSO4. CONCLUSIONS Zn ion is one of the antioxidants in the cell. The results of our current clinical study are sufficient to demonstrate that Zn can improve preserves sperm quality during cryopreservation when added to GEYC. The addition of 50 µM ZnSO4 increased curve velocity, mean path velocity, sperm survival (or plasma membrane integrity), and mitochondrial membrane potential while reducing ROS production and DNA breaks compared to GEYC thawed without ZnSO4.


Subject(s)
Cryopreservation , Cryoprotective Agents , DNA Fragmentation , Membrane Potential, Mitochondrial , Reactive Oxygen Species , Semen Preservation , Sperm Motility , Spermatozoa , Zinc , Male , Cryopreservation/methods , Humans , Spermatozoa/drug effects , Spermatozoa/metabolism , Cryoprotective Agents/pharmacology , Reactive Oxygen Species/metabolism , Sperm Motility/drug effects , Semen Preservation/methods , Membrane Potential, Mitochondrial/drug effects , DNA Fragmentation/drug effects , Zinc/pharmacology , Zinc/metabolism , Cell Membrane/drug effects , Cell Membrane/metabolism , Semen Analysis , Cell Survival/drug effects , Adult , Mitochondria/drug effects , Mitochondria/metabolism , Acrosome/drug effects , Acrosome/metabolism , Freezing
11.
Sci Rep ; 14(1): 12253, 2024 May 28.
Article in English | MEDLINE | ID: mdl-38806545

ABSTRACT

Overexpression of Glycine max disease resistant 1 (GmDR1) exhibits broad-spectrum resistance against Fusarium virguliforme, Heterodera glycines (soybean cyst nematode), Tetranychus urticae (Koch) (spider mites), and Aphis glycines Matsumura (soybean aphids) in soybean. To understand the mechanisms of broad-spectrum immunity mediated by GmDR1, the transcriptomes of a strong and a weak GmDR1-overexpressor following treatment with chitin, a pathogen- and pest-associated molecular pattern (PAMP) common to these organisms, were investigated. The strong and weak GmDR1-overexpressors exhibited altered expression of 6098 and 992 genes, respectively, as compared to the nontransgenic control following chitin treatment. However, only 192 chitin- and 115 buffer-responsive genes exhibited over two-fold changes in expression levels in both strong and weak GmDR1-overexpressors as compared to the control. MapMan analysis of the 192 chitin-responsive genes revealed 64 biotic stress-related genes, of which 53 were induced and 11 repressed as compared to the control. The 53 chitin-induced genes include nine genes that encode receptor kinases, 13 encode nucleotide-binding leucine-rich repeat (NLR) receptor proteins, seven encode WRKY transcription factors, four ethylene response factors, and three MYB-like transcription factors. Investigation of a subset of these genes revealed three receptor protein kinases, seven NLR proteins, and one WRKY transcription factor genes that are induced following F. virguliforme and H. glycines infection. The integral plasma membrane GmDR1 protein most likely recognizes PAMPs including chitin and activates transcription of genes encoding receptor kinases, NLR proteins and defense-related genes. GmDR1 could be a pattern recognition receptor that regulates the expression of several NLRs for expression of PAMP-triggered immunity and/or priming the effector triggered immunity.


Subject(s)
Disease Resistance , Gene Expression Regulation, Plant , Glycine max , NLR Proteins , Plant Diseases , Plant Proteins , Glycine max/parasitology , Glycine max/genetics , Disease Resistance/genetics , Plant Diseases/parasitology , Plant Diseases/microbiology , Plant Diseases/genetics , Plant Proteins/genetics , Plant Proteins/metabolism , NLR Proteins/metabolism , NLR Proteins/genetics , Animals , Fusarium , Chitin/metabolism , Cell Membrane/metabolism , Transcriptome , Plants, Genetically Modified
12.
Mol Biol Rep ; 51(1): 679, 2024 May 25.
Article in English | MEDLINE | ID: mdl-38796668

ABSTRACT

BACKGROUND: Renal ischemia-reperfusion injury (IRI) is one of the causes of acute kidney injury. Annexin A5 (AnxA5), a calcium-dependent cell membrane-binding protein, shows protective effects in various organ IRI models. This study explored the therapeutic effect of exogenous AnxA5 monomer protein on renal IRI and its potential mechanism of action. METHODS AND RESULTS: Different doses of AnxA5 were injected intravenously to treat bilateral renal IRI in SD rats. This model confirmed the protective effects of AnxA5 on kidney structure and function. In vitro, HK-2 cells were subjected to hypoxia for 12 h, followed by restoration of normal oxygen supply to simulate IRI. In vitro experiments demonstrated the mechanism of action of AnxA5 by measuring cellular activity and permeability. A comparison of the mutant AnxA5 protein M23 and the application of a calcium-free culture medium further validated the protective effect of AnxA5 by forming a network structure. CONCLUSIONS: Exogenous AnxA5 monomers prevented renal IRI by binding to the damaged renal tubular epithelial cell membrane, forming a two-dimensional network structure to maintain cell membrane integrity, and ultimately prevent cell death.


Subject(s)
Annexin A5 , Kidney , Rats, Sprague-Dawley , Reperfusion Injury , Animals , Reperfusion Injury/drug therapy , Reperfusion Injury/metabolism , Rats , Annexin A5/metabolism , Annexin A5/pharmacology , Humans , Kidney/metabolism , Kidney/drug effects , Kidney/pathology , Male , Cell Membrane/metabolism , Cell Membrane/drug effects , Cell Line , Acute Kidney Injury/drug therapy , Acute Kidney Injury/metabolism , Acute Kidney Injury/pathology , Disease Models, Animal
13.
Biotechnol J ; 19(5): e2400098, 2024 May.
Article in English | MEDLINE | ID: mdl-38797728

ABSTRACT

Human carboxypeptidase B1 (hCPB1) is vital for recombinant insulin production, holding substantial value in the pharmaceutical industry. Current challenges include limited hCPB1 enzyme activity. In this study, recombinant hCPB1 efficient expression in Pichia pastoris was achieved. To enhance hCPB1 secretion, we conducted signal peptides screening and deleted the Vps10 sortilin domain, reducing vacuolar mis-sorting. Overexpression of Sec4p increased the fusion of secretory vesicles with the plasma membrane and improved hCPB1 secretion by 20%. Rational protein engineering generated twenty-two single-mutation mutants and identified the A178L mutation resulted in a 30% increase in hCPB1 specific activity. However, all combinational mutations that increased specific activities decreased protein expression levels. Therefore, computer-aided global protein design with PROSS was employed for the aim of improving specific activities and preserving good protein expression. Among the six designed mutants, hCPB1-P6 showed a remarkable 114% increase in the catalytic rate constant (kcat), a 137% decrease in the Michaelis constant (Km), and a 490% increase in catalytic efficiency. Most mutations occurred on the surface of hCPB1-P6, with eight sites mutated to proline. In a 5 L fermenter, hCPB1-P6 was produced by the secretion-enhanced P. pastoris chassis to 199.6 ± 20 mg L-1 with a specific activity of 96 ± 0.32 U mg-1, resulting in a total enzyme activity of 19137 ± 1131 U L-1, demonstrating significant potential for industrial applications.


Subject(s)
Carboxypeptidase B , Cell Membrane , Golgi Apparatus , Protein Engineering , Recombinant Proteins , Humans , Recombinant Proteins/genetics , Recombinant Proteins/metabolism , Protein Engineering/methods , Carboxypeptidase B/genetics , Carboxypeptidase B/metabolism , Cell Membrane/metabolism , Cell Membrane/genetics , Golgi Apparatus/metabolism , Golgi Apparatus/genetics , Golgi Apparatus/enzymology , Saccharomycetales/genetics , Saccharomycetales/enzymology , Mutation , Pichia/genetics , Pichia/metabolism , Protein Sorting Signals/genetics , Protein Transport
14.
Biomolecules ; 14(5)2024 May 10.
Article in English | MEDLINE | ID: mdl-38785977

ABSTRACT

Host restriction factor SERINC5 (SER5) incorporates into the HIV-1 membrane and inhibits infectivity by a poorly understood mechanism. Recently, SER5 was found to exhibit scramblase-like activity leading to the externalization of phosphatidylserine (PS) on the viral surface, which has been proposed to be responsible for SER5's antiviral activity. This and other reports that document modulation of HIV-1 infectivity by viral lipid composition prompted us to investigate the role of PS in regulating SER5-mediated HIV-1 restriction. First, we show that the level of SER5 incorporation into virions correlates with an increase in PS levels in the outer leaflet of the viral membrane. We developed an assay to estimate the PS distribution across the viral membrane and found that SER5, but not SER2, which lacks antiviral activity, abrogates PS asymmetry by externalizing this lipid. Second, SER5 incorporation diminished the infectivity of pseudoviruses produced from cells lacking a flippase subunit CDC50a and, therefore, exhibited a higher baseline level of surface-accessible PS. Finally, exogenous manipulation of the viral PS levels utilizing methyl-alpha-cyclodextrin revealed a lack of correlation between external PS and virion infectivity. Taken together, our study implies that the increased PS exposure to SER5-containing virions itself is not directly linked to HIV-1 restriction.


Subject(s)
HIV-1 , Membrane Proteins , Phosphatidylserines , HIV-1/metabolism , Phosphatidylserines/metabolism , Humans , Membrane Proteins/metabolism , Virion/metabolism , HEK293 Cells , Cell Membrane/metabolism , HIV Infections/virology , HIV Infections/metabolism
15.
J Cell Sci ; 137(10)2024 May 15.
Article in English | MEDLINE | ID: mdl-38770683

ABSTRACT

Membrane trafficking, a fundamental cellular process encompassing the transport of molecules to specific organelles, endocytosis at the plasma membrane and protein secretion, is crucial for cellular homeostasis and signalling. Cancer cells adapt membrane trafficking to enhance their survival and metabolism, and understanding these adaptations is vital for improving patient responses to therapy and identifying therapeutic targets. In this Review, we provide a concise overview of major membrane trafficking pathways and detail adaptations in these pathways, including COPII-dependent endoplasmic reticulum (ER)-to-Golgi vesicle trafficking, COPI-dependent retrograde Golgi-to-ER trafficking and endocytosis, that have been found in cancer. We explore how these adaptations confer growth advantages or resistance to cell death and conclude by discussing the potential for utilising this knowledge in developing new treatment strategies and overcoming drug resistance for cancer patients.


Subject(s)
Carcinogenesis , Cell Membrane , Neoplasms , Humans , Neoplasms/metabolism , Neoplasms/pathology , Carcinogenesis/metabolism , Carcinogenesis/pathology , Animals , Cell Membrane/metabolism , Endoplasmic Reticulum/metabolism , Endocytosis , Protein Transport , Golgi Apparatus/metabolism
16.
Sheng Wu Gong Cheng Xue Bao ; 40(5): 1323-1337, 2024 May 25.
Article in Chinese | MEDLINE | ID: mdl-38783800

ABSTRACT

Nanotechnology has attracted increasing attention in the field of medical applications due to its significant potential for development. However, one major challenge that has emerged with nanoparticles is their tendency to activate the host immune clearance system, which hampers the achievement of desired therapeutic outcomes and may lead to harmful side effects. In recent years, membrane-coated nanoparticles have emerged as a promising solution, demonstrating their effectiveness in evading immune system clearance. These innovative nanoparticles inherit essential biological attributes from natural cell membranes, such as anchoring proteins and antigens. Consequently, membrane-coated nanoparticles exhibit unique capabilities such as immune evasion, prolonged circulation, targeted drug release, and immune modulation, substantially enhancing their versatility and prospects within the realm of biomedical applications. This review provides a comprehensive overview of the current applications of cell membrane-coated nanoparticles in disease therapy, highlighting their immense potential in this rapidly evolving platform. Additionally, the review outlines the promising prospects of this technology in disease therapy.


Subject(s)
Cell Membrane , Nanoparticles , Nanoparticles/chemistry , Humans , Cell Membrane/metabolism , Drug Delivery Systems , Animals , Neoplasms/therapy , Nanotechnology/methods
17.
PLoS One ; 19(5): e0303567, 2024.
Article in English | MEDLINE | ID: mdl-38776323

ABSTRACT

Spermatozoa cryopreservation has been practiced for decades and is a very useful technique for long-term preservation of sperm fertility. The capability for semen cryopreservation varies across species, seasons, latitudes, and even for different ejaculates from the same animal. This article summarizes research results on sperm cryotolerance biomarkers in several species, focusing on three areas: spermatozoa cryotolerance biomarkers, seminal plasma proteins cryotolerance biomarkers, and other cryotolerance biomarkers. We discovered that sperm cryoresistance biomarkers are primarily related to sperm plasma membrane stability, the presence of antioxidant substances in sperm or seminal plasma, sperm cell energy metabolism, water and small molecule transport channels in the sperm plasma membrane, and antistress substances in sperm or seminal plasma. The research conducted using diverse livestock models can be employed to enhance the basic and applied reproduction of other mammals through the study of sperm cryotolerance biomarkers, as well as the substantial similarities between livestock and other organisms, including endangered species.


Subject(s)
Biomarkers , Cryopreservation , Semen Preservation , Semen , Spermatozoa , Cryopreservation/methods , Male , Biomarkers/metabolism , Semen Preservation/methods , Animals , Semen/metabolism , Spermatozoa/metabolism , Humans , Cell Membrane/metabolism
18.
Langmuir ; 40(20): 10600-10614, 2024 May 21.
Article in English | MEDLINE | ID: mdl-38721840

ABSTRACT

Brominated flame retardants (BFRs) are small organic molecules containing several bromine substituents added to plastics to limit their flammability. BFRs can constitute up to 30% of the weight of some plastics, which is why they are produced in large quantities. Along with plastic waste and microplastic particles, BFRs end up in the soil and can easily leach causing contamination. As polyhalogenated molecules, multiple BFRs were classified as persistent organic pollutants (POPs), meaning that their biodegradation in the soils is especially challenging. However, some anaerobic bacteria as Dehaloccocoides can dehalogenate BFRs, which is important in the bioremediation of contaminated soils. BFRs are hydrophobic, can accumulate in plasma membranes, and disturb their function. On the other hand, limited membrane accumulation is necessary for BFR dehalogenation. To study the BFR-membrane interaction, we created membrane models of soil dehalogenating bacteria and tested their interactions with seven legacy and novel BFRs most common in soils. Phospholipid Langmuir monolayers with appropriate composition were used as membrane models. These membranes were doped in the selected BFRs, and the incorporation of BFR molecules into the phospholipid matrix and also the effects of BFR presence on membrane physical properties and morphology were studied. It turned out that the seven BFRs differed significantly in their membrane affinity. For some, the incorporation was very limited, and others incorporated effectively and could affect membrane properties, while one of the tested molecules induced the formation of bilayer domains in the membranes. Thus, Langmuir monolayers can be effectively used for pretesting BFR membrane activity.


Subject(s)
Flame Retardants , X-Ray Diffraction , Flame Retardants/metabolism , Halogenation , Cell Membrane/metabolism , Cell Membrane/chemistry
19.
Biomed Mater ; 19(4)2024 May 23.
Article in English | MEDLINE | ID: mdl-38740051

ABSTRACT

Infectious diseases severely threaten human health, and traditional treatment techniques face multiple limitations. As an important component of immune cells, macrophages display unique biological properties, such as biocompatibility, immunocompatibility, targeting specificity, and immunoregulatory activity, and play a critical role in protecting the body against infections. The macrophage membrane-coated nanoparticles not only maintain the functions of the inner nanoparticles but also inherit the characteristics of macrophages, making them excellent tools for improving drug delivery and therapeutic implications in infectious diseases (IDs). In this review, we describe the characteristics and functions of macrophage membrane-coated nanoparticles and their advantages and challenges in ID therapy. We first summarize the pathological features of IDs, providing insight into how to fight them. Next, we focus on the classification, characteristics, and preparation of macrophage membrane-coated nanoparticles. Finally, we comprehensively describe the progress of macrophage membrane-coated nanoparticles in combating IDs, including drug delivery, inhibition and killing of pathogens, and immune modulation. At the end of this review, a look forward to the challenges of this aspect is presented.


Subject(s)
Cell Membrane , Communicable Diseases , Drug Delivery Systems , Macrophages , Nanoparticles , Humans , Nanoparticles/chemistry , Macrophages/metabolism , Animals , Communicable Diseases/drug therapy , Cell Membrane/metabolism , Coated Materials, Biocompatible/chemistry
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