Membrane stiffness is one of the key determinants of E coli MscS channel echanosensitivity

Publication date: Available online 22 January 2020Source: Biochimica et Biophysica Acta (BBA) - BiomembranesAuthor(s): Feng Xue, Charles D. Cox, Navid Bavi, Paul R. Rohde, Yoshitaka Nakayama, Boris MartinacAbstractMechanosensitive (MS) channels have an intimate relationship with membrane lipids that underlie their mechanosensitivity. Membrane lipids may influence channel activity by directly interacting with MS channels or by influencing the global properties of the membrane such as elastic area expansion modulus or bending rigidity. Previous work has implicated membrane stiffness as a potential determinant of the mechanosensitivity of E. coli (Ec)MscS. Here we systematically tested this hypothesis using patch fluorometry of azolectin liposomes doped with lipids of increasing elastic area expansion modulus. Increasing dioleoylphosphatidylethanolamine (DOPE) content of azolectin liposomes made it more difficult to activate EcMscS by membrane tension (i.e. increased gating threshold). This effect was exacerbated by stiffer forms of phosphatidylethanolamine such as the branched chain lipid diphytanoylphosphoethanolamine (DPhPE) or the fully saturated lipid distearoyl-sn-glycero-3-phosphoethanolamine (DSPE). Furthermore, a comparison of the branched chain lipid diphytanoylphosphocholine (DPhPC) to the stiffer DPhPE indicated again that it was harder to activate EcMscS in the presence of the stiffer DPhPE. We show that these effects are not due to changes in membrane bending rigid...
Source: Biochimica et Biophysica Acta (BBA) Biomembranes - Category: Biochemistry Source Type: research

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Contributors : Samuel Jacques ; Almer M van der Sloot ; Caroline Huard ; Jasmin Coulombe-Huntington ; Sarah Tsao ; Sylvain Tollis ; Thierry Bertomeu ; Elizabeth J Culp ; Daniel Pallant ; Michael A Cook ; Eric Bonneil ; Pierre Thibault ; Gerard D Wright ; Michael TyersSeries Type : OtherOrganism : Homo sapiensSystematic genetic interaction profiles can reveal the mechanism-of-action of bioactivecompounds. The imipridone ONC201, which is currently in cancer clinical trials, has beenascribed a variety of different targets. To investigate the genetic dependencies of imipridoneaction, we screened a genome-wide CRISPR knockout l...
Source: GEO: Gene Expression Omnibus - Category: Genetics & Stem Cells Tags: Other Homo sapiens Source Type: research
ConclusionsAn alarming rate of phenotypic resistance was observed in this study. Many isolates were positive for the screened resistance genes. According to the phylogenetic background, most resistant isolates belonged to the commensal phylo-types, representing significant role of commensal strains as a source of resistance genes. These findings highlight the role of pigeon as disseminator of resistant E. coli strains.
Source: Journal of Global Antimicrobial Resistance - Category: Infectious Diseases Source Type: research
Publication date: Available online 22 February 2020Source: Biotechnology ReportsAuthor(s): Valdemir M. Cardoso, Gilson Campani, Maurício P. Santos, Gabriel G. Silva, Manuella C. Pires, Viviane M. Gonçalves, Roberto de C. Giordano, Cíntia R. Sargo, AntônioC.L. Horta, Teresa C. ZangirolamiAbstractThe impact of cultivation strategy on the cost of recombinant protein production is crucial for defining cost-effective bioreactor operation conditions. This paper presents a methodology to estimate and compare cost impacts related to utilities as well as medium composition, using simple design equations a...
Source: Biotechnology Reports - Category: Biotechnology Source Type: research
In this study, the outer membrane from E. coli was isolated and used to produce OM particles with a diameter of approximately 100 nm. These prepared OM particles were applied in a thermophoretic immunoassay. First, outer membrane (OM) particles with lipopolysaccharides (LPS) and anti-LPS antibodies were used as a model to demonstrate proof of concept and the difference in E. coli thermophoresis was explained by the changes in the molecular surface area (A) and effective charge (σeff). The hydrodynamic size of the molecules was measured as a changing parameter, molecular surface area (A), by dynamic laser scattering...
Source: Biosensors and Bioelectronics - Category: Biotechnology Source Type: research
Publication date: Available online 22 February 2020Source: Biochemical Engineering JournalAuthor(s): Francesco Maluta, Maxime Pigou, Giuseppina Montante, Jrme MorchainAbstractA simple Interaction by Exchange with the Mean (IEM) mixing model is implemented to describe the glucose concentration segregations in industrial and laboratory scale bioreactors. This approach is coupled with a Population Balance Model (PBM) for the growth rate adaptation and a metabolic model dependent on the individuals state, both from the literature [1]. The model formulation is validated against different published experiments and it is shown th...
Source: Biochemical Engineering Journal - Category: Biochemistry Source Type: research
In conclusion, taller body height at the entry to adulthood, supposed to be a marker of early-life environment, is associated with lower risk of dementia diagnosis later in life. The association persisted when adjusted for educational level and intelligence test scores in young adulthood, suggesting that height is not just acting as an indicator of cognitive reserve. A Comparison of Biological Age Measurement Approaches https://www.fightaging.org/archives/2020/02/a-comparison-of-biological-age-measurement-approaches/ Researchers here assess the performance of a range of approaches to measuring biological...
Source: Fight Aging! - Category: Research Authors: Tags: Newsletters Source Type: blogs
This article reports an 82-year-old male with a mechanical aortic valve replacement who was admitted for fever and fatigue. He was diagnosed with a tricuspid valve endocarditis caused by an extended spectrum beta lactamase producing Escherichia coli following positive blood cultures and echocardiography. He received six weeks of imipenem / cilastatin and subsequently improved and was discharged with ambulatory follow ups with his infectious disease specialist.
Source: IDCases - Category: Infectious Diseases Source Type: research
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Source: Phytomedicine - Category: Drugs & Pharmacology Source Type: research
Publication date: Available online 22 February 2020Source: Materials LettersAuthor(s): Li Chen, Hong Pan, Caifeng Zhuang, Mengyao Peng, Li ZhangAbstractTreatment against bacterial infection is of great significance for joint wound healing in medical nursing care. Thus, it is urgent to develop efficient antibacterial agent with excellent wound healing capability. In this research, a two-step strategy was employed for the development of novel chitosan scaffold reinforced by strontium doped TiO2 nanoparticles (CS/Sr-TiO2). The antibacterial activity of CS/Sr-TiO2 against Escherichia coli, and Staphylococcus aureus were evalua...
Source: Materials Letters - Category: Materials Science Source Type: research
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Source: Biotechnology Progress - Category: Biotechnology Authors: Tags: RESEARCH ARTICLE Source Type: research
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