Bacterial Model Membranes Deform (resp. Persist) upon Ni2+Binding to Inner Core (resp. O-Antigen) of Lipopolysaccharides

2019 ◽  
Vol 123 (19) ◽  
pp. 4258-4270 ◽  
Author(s):  
HanByul Chang ◽  
Karthikeyan Gnanasekaran ◽  
Nathan C. Gianneschi ◽  
Franz M. Geiger
Keyword(s):  
Inner Core ◽  
Model Membranes ◽  
O Antigen ◽  
Bacterial Model

Bacterial Model Membranes Reshape Fibrillation of a Functional Amyloid Protein

Biochemistry ◽  
2018 ◽  
Vol 57 (35) ◽  
pp. 5230-5238 ◽  
Author(s):  
Ravit Malishev ◽  
Razan Abbasi ◽  
Raz Jelinek ◽  
Liraz Chai
Keyword(s):  
Model Membranes ◽  
Amyloid Protein ◽  
Functional Amyloid ◽  
Bacterial Model

scholarly journals Dewetting-Induced Formation of Bacterial Model Membranes using Submicron Shell Double Emulsions

2019 ◽  
Vol 116 (3) ◽  
pp. 226a
Author(s):  
Sepehr Maktabi ◽  
Noah Malmstadt ◽  
Jeffrey Schertzer ◽  
Paul Chiarot
Keyword(s):  
Model Membranes ◽  
Double Emulsions ◽  
Bacterial Model

scholarly journals Study of the solubilisation process of bacterial model membranes induced by DDAO

2021 ◽  
Vol 0 (0) ◽  
Author(s):  
K. Želinská ◽  
J. Gallová
Keyword(s):  
Light Scattering ◽  
Partition Coefficient ◽  
Model Membrane ◽  
Model Membranes ◽  
Static Light Scattering ◽  
Molar Ratio ◽  
Bacterial Model

Abstract Solubilisation of two bacterial model membranes induced by N,N-dimethyl-1-dodecanamine-N-oxide (DDAO) was studied. The first model membrane consisted of a mixture of palmitoyloleoylphosphatidylethanolamine (POPE) and palmitoyloleoylphosphatidylglycerol (POPG) in a molar ratio 0.6:0.4 mol/mol, and a second model membrane was enriched with tetraoleoylcardiolipin (TOCL) with a composition POPE-POPG-TOCL = 0.67:0.23:0.1 mol/mol/mol. Solubilisation of these model membranes was studied by static light scattering (nephelometry). Effective ratio Re (the amount of DDAO integrated into the bilayer to the amount of lipid) at different steps of the solubilisation process was determined. The molar partition coefficient of DDAO was calculated – in case of the POPE-POPG membrane, Kp = 5,300 ± 400, for the POPE-POPG-TOCL membrane, Kp = 6,500 ± 500.

scholarly journals Lipopolysaccharide Domains Modulate Urovirulence

2016 ◽  
Vol 84 (11) ◽  
pp. 3131-3140 ◽  
Author(s):  
Lizath M. Aguiniga ◽  
Ryan E. Yaggie ◽  
Anthony J. Schaeffer ◽  
David J. Klumpp
Keyword(s):  
Immune Responses ◽  
Inner Core ◽  
Outer Core ◽  
Structural Determinants ◽  
Content Type ◽  
Interleukin 33 ◽  
Link Type ◽  
O Antigen ◽  
Tract Infections

Uropathogenic Escherichia coli (UPEC) accounts for 80 to 90% of urinary tract infections (UTI), and the increasing rate of antibiotic resistance among UPEC isolates reinforces the need for vaccines to prevent UTIs and recurrent infections. Previous studies have shown that UPEC isolate NU14 suppresses proinflammatory NF-κB-dependent cytokines (D. J. Klumpp, A. C. Weiser, S. Sengupta, S. G. Forrestal, R. A. Batler, and A. J. Schaeffer, Infect Immun 69:6689–6695, 2001, http://dx.doi.org/10.1128/IAI.69.11.6689-6695.2001 ; B. K. Billips, A. J. Schaeffer, and D. J. Klumpp, Infect Immun 76:3891–3900, 2008, http://dx.doi.org/10.1128/IAI.00069-08 ). However, modification of lipopolysaccharide (LPS) structure by deleting the O-antigen ligase gene ( waaL ) enhanced proinflammatory cytokine secretion. Vaccination with the Δ waaL mutant diminished NU14 reservoirs and protected against subsequent infections. Therefore, we hypothesized that LPS structural determinants shape immune responses. We evaluated the contribution of LPS domains to urovirulence corresponding to the inner core ( waaP , waaY , and rfaQ ), outer core ( rfaG ), and O-antigen ( waaL , wzzE , and wzyE ). Deletion of waaP , waaY , and rfaG attenuated adherence to urothelial cells in vitro . In a murine UTI model, the Δ rfaG mutant had the most severe defect in colonization. The mutation of rfaG , waaL , wzzE , and wzyE resulted in an inability to form reservoirs in mouse bladders. Infection with the LPS mutant panel resulted in various levels of urinary myeloperoxidase. Since the Δ waaL mutant promoted Th 1 -associated adaptive responses in previous studies (B. K. Billips, R. E. Yaggie, J. P. Cashy, A. J. Schaeffer, and D. J. Klumpp, J Infect Dis 200:263–272, 2009, http://dx.doi.org/10.1086/599839 ), we assessed NU14 for Th 2 -associated cytokines. We found NU14 infection stimulated TLR4-dependent bladder interleukin-33 (IL-33) production. Inoculation with rfaG , waaL , wzzE , and wzyE mutants showed decreased IL-33 production. We quantified antigen-specific antibodies after infection and found significantly increased IgE and IgG1 in Δ waaP mutant-infected mice. Our studies show LPS structural constituents mediate multiple aspects of the UPEC life cycle, including the ability to acutely colonize bladders, form reservoirs, and evoke innate and adaptive immune responses.

scholarly journals The lipopolysaccharide of the mastitis isolate Escherichia coli strain 1303 comprises a novel O-antigen and the rare K-12 core type

Microbiology ◽  
2011 ◽  
Vol 157 (6) ◽  
pp. 1750-1760 ◽  
Author(s):  
Katarzyna A. Duda ◽  
Buko Lindner ◽  
Helmut Brade ◽  
Andreas Leimbach ◽  
Elżbieta Brzuszkiewicz ◽  
...  
Keyword(s):  
Escherichia Coli ◽  
Inner Core ◽  
Bovine Mastitis ◽  
Outer Core ◽  
Coli Strain ◽  
Core Oligosaccharide ◽  
2D Nmr Spectroscopy ◽  
E Coli ◽  
O Antigen ◽  
K 12

Mastitis represents one of the most significant health problems of dairy herds. The two major causative agents of this disease are Escherichia coli and Staphylococcus aureus. Of the first, its lipopolysaccharide (LPS) is thought to play a prominent role during infection. Here, we report the O-antigen (OPS, O-specific polysaccharide) structure of the LPS from bovine mastitis isolate E. coli 1303. The structure was determined utilizing chemical analyses, mass spectrometry, and 1D and 2D NMR spectroscopy methods. The O-repeating unit was characterized as -[→4)-β-d-Quip3NAc-(1→3)-α-l-Fucp2OAc-(1→4)-β-d-Galp-(1→3)-α-d-GalpNAc-(1→]- in which the O-acetyl substitution was non-stoichiometric. The nucleotide sequence of the O-antigen gene cluster of E. coli 1303 was also determined. This cluster, located between the gnd and galF genes, contains 13 putative open reading frames, most of which represent unknown nucleotide sequences that have not been described before. The O-antigen of E. coli 1303 was shown to substitute O-7 of the terminal ld-heptose of the K-12 core oligosaccharide. Interestingly, the non-OPS-substituted core oligosaccharide represented a truncated version of the K-12 outer core – namely terminal ld-heptose and glucose were missing; however, it possessed a third Kdo residue in the inner core. On the basis of structural and genetic data we show that the mastitis isolate E. coli 1303 represents a new serotype and possesses the K-12 core type, which is rather uncommon among human and bovine isolates.

Towards the use of monofluorinated dimyristoylphosphatidylcholines as 19F NMR reporters in bacterial model membranes

2018 ◽  
Vol 206 ◽  
pp. 43-47 ◽  
Author(s):  
Marie-Claude Gagnon ◽  
Paméla Ouellet ◽  
Michèle Auger ◽  
Jean-François Paquin
Keyword(s):  
Model Membranes ◽  
19F Nmr ◽  
Bacterial Model

Characterization of the Core Oligosaccharide and the O-Antigen Biological Repeating Unit from Halomonas stevensii Lipopolysaccharide: The First Case of O-Antigen Linked to the Inner Core

2012 ◽  
Vol 18 (12) ◽  
pp. 3729-3735 ◽  
Author(s):  
Giuseppina Pieretti ◽  
Sara Carillo ◽  
Buko Lindner ◽  
Kwang Kyu Kim ◽  
Keun Chul Lee ◽  
...  
Keyword(s):  
Inner Core ◽  
Core Oligosaccharide ◽  
The Core ◽  
O Antigen ◽  
First Case

scholarly journals Bacteriocin enterocin CRL35 is a modular peptide that induces non-bilayer states in bacterial model membranes

2020 ◽  
Vol 1862 (2) ◽  
pp. 183135 ◽  
Author(s):  
Carolina Medina Amado ◽  
Carlos J. Minahk ◽  
Eduardo Cilli ◽  
Rafael G. Oliveira ◽  
Fernando G. Dupuy
Keyword(s):  
Model Membranes ◽  
Bacterial Model
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