keyword
MENU ▼
Read by QxMD icon Read
search

Pore forming toxins

keyword
https://www.readbyqxmd.com/read/29150505/cry64ba-and-cry64ca-two-etx-mtx2-bacillus-thuringiensis-insecticidal-proteins-against-hemipteran-pests
#1
Yonglei Liu, Yinglong Wang, Changlong Shu, Kejian Lin, Fuping Song, Alejandra Bravo, Mario Soberón, Jie Zhang
Genetically modified crops that express insecticidal Bacillus thuringiensis (Bt) proteins have become a primary approach for control of lepidopteran (moth) and coleopteran (beetle) pests that feed by chewing the plants. However, the sap-sucking insects (Hemiptera) are not particularly susceptible to Bt toxins. In this study, we describe two Cry toxins (Cry64Ba and Cry64Ca) from a Bt 1012 strain showed toxicity against two important rice hemipteran pests, Laodelphax striatellus and Sogatella furcifera Both of these two proteins contain an ETX/MTX2 domain, and share common sequence features with the β-pore forming toxins...
November 17, 2017: Applied and Environmental Microbiology
https://www.readbyqxmd.com/read/29148811/continuous-pore-spanning-lipid-bilayers-on-silicon-oxide-coated-porous-substrates
#2
Nelli Teske, Jeremias Sibold, Johannes Schumacher, Nikolas K Teiwes, Martin Gleisner, Ingo P Mey, Claudia Steinem
A number of techniques has been developed and analyzed in recent years to generate pore-spanning membranes (PSMs). While quite a number of methods rely on nanoporous substrates, only a few use micrometer-sized pores to be able to individually resolve suspending membranes by means of fluorescence microscopy. To be able to produce PSMs on pores that are micrometer in size, an orthogonal functionalization strategy resulting in a hydrophilic surface is highly desirable. Here, we report on a method to prepare PSMs based on the evaporation of a thin layer of silicon monoxide on top of the porous substrate...
November 17, 2017: Langmuir: the ACS Journal of Surfaces and Colloids
https://www.readbyqxmd.com/read/29138096/one-single-salt-bridge-explains-the-different-cytolytic-activities-shown-by-actinoporins-sticholysin-i-and-ii-from-the-venom-of-stichodactyla-helianthus
#3
Esperanza Rivera-de-Torre, Juan Palacios-Ortega, Sara García-Linares, José G Gavilanes, Álvaro Martínez-Del-Pozo
Sticholysins I and II (StnI and StnII), α-pore forming toxins from the sea anemone Stichodactyla helianthus, are water-soluble toxic proteins which upon interaction with lipid membranes of specific composition bind to the bilayer, extend and insert their N-terminal α-helix, and become oligomeric integral membrane structures. The result is a pore that leads to cell death by osmotic shock. StnI and StnII show 93% of sequence identity, but also different membrane pore-forming activities. The hydrophobicity profile along the first 18 residues revealed differences which were canceled by substituting StnI amino acids 2 and 9...
November 11, 2017: Archives of Biochemistry and Biophysics
https://www.readbyqxmd.com/read/29120408/exolysin-shapes-the-virulence-of-pseudomonas-aeruginosa-clonal-outliers
#4
REVIEW
Emeline Reboud, Pauline Basso, Antoine P Maillard, Philippe Huber, Ina Attrée
Bacterial toxins are important weapons of toxicogenic pathogens. Depending on their origin, structure and targets, they show diverse mechanisms of action and effects on eukaryotic cells. Exolysin is a secreted 170 kDa pore-forming toxin employed by clonal outliers of Pseudomonas aeruginosa providing to some strains a hyper-virulent behaviour. This group of strains lacks the major virulence factor used by classical strains, the Type III secretion system. Here, we review the structural features of the toxin, the mechanism of its secretion and the effects of the pore formation on eukaryotic cells...
November 9, 2017: Toxins
https://www.readbyqxmd.com/read/29117526/lysenin-toxin-membrane-insertion-is-ph-dependent-but-independent-of-neighboring-lysenins
#5
Ignacio L B Munguira, Hirohide Takahashi, Ignacio Casuso, Simon Scheuring
Pore-forming toxins form a family of proteins that act as virulence factors of pathogenic bacteria, but similar proteins are found in all kingdoms of life, including the vertebrate immune system. They are secreted as soluble monomers that oligomerize on target membranes in the so-called prepore state; after activation, they insert into the membrane and adopt the pore state. Lysenin is a pore-forming toxin from the earthworm Eisenida foetida, of which both the soluble and membrane-inserted structures are solved...
November 7, 2017: Biophysical Journal
https://www.readbyqxmd.com/read/29114985/coordinated-delivery-and-function-of-bacterial-martx-toxin-effectors
#6
REVIEW
Patrick J Woida, Karla J F Satchell
Bacteria often coordinate virulence factors to fine-tune the host response during infection. These coordinated events can include toxins counteracting or amplifying effects of another toxin or though regulating the stability of virulence factors to remove their function once it is no longer needed. Multifunctional autoprocessing repeats-in toxin (MARTX) toxins are effector delivery toxins that form a pore into the plasma membrane of a eukaryotic cell to deliver multiple effector proteins into the cytosol of the target cell...
November 8, 2017: Molecular Microbiology
https://www.readbyqxmd.com/read/29111771/staphylococcus-aureus-alpha-toxin-induces-actin-filament-remodeling-in-human-airway-epithelial-model-cells
#7
Sabine Ziesemer, Ina Eiffler, Alfrun Schönberg, Christian Müller, Falko Hochgräfe, Achim G Beule, Jan-Peter Hildebrandt
Exposure of cultured human airway epithelial model cells (16HBE14o-, S9) to Staphylococcus aureus alpha-toxin (hemolysin A, Hla) induces changes in cell morphology and cell layer integrity which are due to the inability of the cells to maintain stable cell-cell or focal contacts and to properly organize their actin cytoskeleton. The aim of this study was to identify Hla-activated signaling pathways involved in regulating the phosphorylation level of the actin depolymerizing factor cofilin. We used recombinant wild-type Hla (rHla) as well as a variant of Hla (rHla-H35L) that is unable to form functional transmembrane pores to treat immortalized human airway epithelial cells (16HBE14o-, S9) as well as freshly isolated human nasal tissue...
November 7, 2017: American Journal of Respiratory Cell and Molecular Biology
https://www.readbyqxmd.com/read/29102330/oral-vaccination-of-broiler-chickens-against-necrotic-enteritis-using-a-non-virulent-netb-positive-strain-of-clostridium-perfringens-type-a
#8
Neha Mishra, Joan A Smyth
Necrotic enteritis (NE) is a severe disease of chickens and turkeys caused by some strains of Clostridium perfringens type A. The disease is well controlled by the use of in-feed antibiotic growth promoters (AGPs). However, due to worldwide public and regulatory pressure to reduce the use of AGPs inter alia, there is an urgent need to develop non-antibiotic based preventative measures. Vaccination would be a suitable control measure, but currently there is no commercial vaccine. NetB (necrotic enteritis toxin B-like) is a pore-forming toxin produced by C...
November 1, 2017: Vaccine
https://www.readbyqxmd.com/read/29102106/magnolol-protects-channel-catfish-from-aeromonas-hydrophila-infection-via-inhibiting-the-expression-of-aerolysin
#9
Jing Dong, Hao Ding, Yongtao Liu, Qiuhong Yang, Ning Xu, Yibin Yang, Xiaohui Ai
Aeromonas hydrophila is a common zoonotic pathogen which can cause several infections both in human and animals, particular aquatic animals. Antibiotics have been widely used in the treatment of A. hydrophila infections, however, the development of resistance has limited the treatment for these infections. There is an urgent need for novel agents and strategies against these infections. Aerolysin, a pore-forming toxin secreted by most pathogenic A. hydrophila, is known to contribute to the pathogenesis of A...
November 2017: Veterinary Microbiology
https://www.readbyqxmd.com/read/29100712/-quercetin-attenuates-staphylococcus-aureus-virulence-by-reducing-alpha-toxin-secretion
#10
Gabriela Carrada López, Carlos A Castañón Sánchez
Alpha toxin, a pore-forming protein with cytotoxic activity, is one of the major virulence factors secreted by most strains of Staphylococcus aureus. The relevance of this protein in the pathogenesis of pneumonia associated with S.aureus infections has already been established. Therefore, inhibiting alpha toxin secretion can be an alternative for controlling these infections. This study shows that quercetin, a naturally occurring flavonoid, inhibits hemolytic activity in a dose-dependent manner and reduces alpha toxin secretion in culture supernatants of methicillin-sensitive and methicillin-resistant S...
October 31, 2017: Revista Argentina de Microbiología
https://www.readbyqxmd.com/read/29099326/disarming-staphylococcus-aureus-from-destroying-human-cells-by-simultaneously-neutralizing-six-cytotoxins-with-two-human-monoclonal-antibodies
#11
Harald Rouha, Susanne Weber, Philipp Janesch, Barbara Maierhofer, Karin Gross, Ivana Dolezilkova, Irina Mirkina, Zehra C Visram, Stefan Malafa, Lukas Stulik, Adriana Badarau, Eszter Nagy
Pathogenesis of Staphylococcus aureus is increasingly recognized to be driven by powerful toxins. Staphylococcus aureus employs up to six pore-forming toxins to subvert the human host defense and to promote bacterial invasion: alpha-hemolysin that disrupts epithelial and endothelial barriers and five leukocidins that lyse phagocytes involved in bacterial clearance. Previously, we described two human monoclonal antibodies (mAbs), ASN-1 that neutralizes alpha-hemolysin and four leukocidins (LukSF-PV, LukED, HlgAB, HlgCB), and ASN-2 that inactivates the 5(th) leukocidin, LukGH...
November 3, 2017: Virulence
https://www.readbyqxmd.com/read/29066778/structural-physicochemical-and-dynamic-features-conserved-within-the-aerolysin-pore-forming-toxin-family
#12
Nuria Cirauqui, Luciano A Abriata, F Gisou van der Goot, Matteo Dal Peraro
Aerolysin is the founding member of a major class of β-pore-forming toxins (β-PFTs) found throughout all kingdoms of life. PFTs are cytotoxic proteins produced as soluble monomers, which oligomerize at the membrane of target host cells forming pores that may lead to osmotic lysis and cell death. Besides their role in microbial infection, they have become interesting for their potential as biotechnological sensors and delivery systems. Using an approach that integrates bioinformatics with molecular modeling and simulation, we looked for conserved features across this large toxin family...
October 24, 2017: Scientific Reports
https://www.readbyqxmd.com/read/29048353/p2x-receptor-antagonists-inhibit-the-interaction-of-s-aureus-hemolysin-a-with-membranes
#13
Markus Schwiering, Matthias Husmann, Nadja Hellmann
The pore forming hemolysin A, Hla, is a major virulence factor of Staphylococcus aureus. Apparently, 1-2 pore(s) per cell suffice(s) to cause cell death. Accumulated experimental evidence points towards a major role of ATP-gated purinergic receptors (P2XR) for hemolysis caused by Hla, complement and other pore forming proteins, presumably by increasing membrane permeability. Indeed, in experiments employing rabbit erythrocytes, inhibitory concentrations of frequently employed P2XR-antagonists were in a similar range as previously reported for erythrocytes of other species and other toxins...
October 19, 2017: Toxins
https://www.readbyqxmd.com/read/29042493/unraveling-the-self-assembly-of-the-pseudomonas-aeruginosa-xcpq-secretin-periplasmic-domain-provides-new-molecular-insights-into-type-ii-secretion-system-secreton-architecture-and-dynamics
#14
Badreddine Douzi, Nhung T T Trinh, Sandra Michel-Souzy, Aline Desmyter, Geneviève Ball, Pascale Barbier, Artemis Kosta, Eric Durand, Katrina T Forest, Christian Cambillau, Alain Roussel, Romé Voulhoux
The type II secretion system (T2SS) releases large folded exoproteins across the envelope of many Gram-negative pathogens. This secretion process therefore requires specific gating, interacting, and dynamics properties mainly operated by a bipartite outer membrane channel called secretin. We have a good understanding of the structure-function relationship of the pore-forming C-terminal domain of secretins. In contrast, the high flexibility of their periplasmic N-terminal domain has been an obstacle in obtaining the detailed structural information required to uncover its molecular function...
October 17, 2017: MBio
https://www.readbyqxmd.com/read/29033912/the-infectious-basis-of-acpa-positive-rheumatoid-arthritis
#15
REVIEW
Lazaros I Sakkas, Dimitrios Daoussis, Stamatis-Nick Liossis, Dimitrios P Bogdanos
Rheumatoid arthritis (RA) is associated with HLA-DRB1 shared epitope (HLA-DRB1SE) and anti-citrullinated protein autoantibodies (ACPAs). ACPAs precedes the onset of clinical and subclinical RA. There are strong data for three infectious agents as autoimmunity triggers in RA, namely Porphyromonas gingivalis and Aggregatibacter actinomycetemcomitans causes of periodontal disease (PD), and Epstein-Barr virus (EBV). P. gingivalis expresses arginine gingipains, that cleave proteins at the arginine residues, and peptidyl arginine deiminase (PPAD), which citrullinates arginine residues of proteins, thus forming neoantigens that lead to ACPA production...
2017: Frontiers in Microbiology
https://www.readbyqxmd.com/read/29030439/conjugation-mediated-horizontal-gene-transfer-of-clostridium-perfringens-plasmids-in-the-chicken-gastrointestinal-tract-results-in-the-formation-of-new-virulent-strains
#16
Jake A Lacey, Anthony L Keyburn, Mark E Ford, Ricardo W Portela, Priscilla A Johanesen, Dena Lyras, Robert J Moore
Clostridium perfringens is a gastrointestinal pathogen capable of causing disease in a variety of hosts. Necrotic enteritis in chickens is caused by C. perfringens strains that produce the pore-forming toxin NetB, the major virulence factor for this disease. Like many other C. perfringens toxins and antibiotic resistance genes, NetB is encoded on a conjugative plasmid. Conjugative transfer of the netB-containing plasmid pJIR3535 has been demonstrated in vitro with a netB null mutant. This study has investigated the effect of plasmid transfer on disease pathogenesis, with two genetically distinct transconjugants constructed under in vitro conditions, within the intestinal tract of chickens...
October 13, 2017: Applied and Environmental Microbiology
https://www.readbyqxmd.com/read/29029417/anti-tumor-activity-of-anthrax-toxin-variants-that-form-a-functional-translocation-pore-by-intermolecular-complementation
#17
Shihui Liu, Qian Ma, Rasem Fattah, Thomas H Bugge, Stephen H Leppla
Anthrax lethal toxin is a typical A-B type protein toxin secreted by Bacillus anthracis. Lethal factor (LF) is the catalytic A-subunit, a metalloprotease having MEKs as targets. LF relies on the cell-binding B-subunit, protective antigen (PA), to gain entry into the cytosol of target cells. PA binds to cell surface toxin receptors and is activated by furin protease to form an LF-binding-competent oligomer-PA pre-pore, which converts to a functional protein-conductive pore in the acidic endocytic vesicles, allowing translocation of LF into the cytosol...
September 12, 2017: Oncotarget
https://www.readbyqxmd.com/read/29026495/recombinant-production-and-affinity-purification-of-the-frac-pore-forming-toxin-using-hexa-his-tag-and-pet-expression-cassette
#18
Mehdi Imani, Hossein Zarei Jaliani, Mohammad Hassan Kheirandish, Mahnaz Azadpour
OBJECTIVES: A newly-introduced protein toxin from a sea anemone, namely fragaceatoxin C is a protein with molecular weight of 20 kDa and pore-forming capability against cell membranes has recently grasped great attentions for its function. In this study, its coding sequence cloned as a fusion protein with His-tag for simple production and rapid purification. MATERIALS AND METHODS: After PCR amplification using NcoI and HindIII-harboring primers, the gene fragment was cloned into pET-28a(+)...
April 2017: Iranian Journal of Basic Medical Sciences
https://www.readbyqxmd.com/read/28988777/delta-toxin-from-clostridium-perfringens-perturbs-intestinal-epithelial-barrier-function-in-caco-2-cell-monolayers
#19
Soshi Seike, Masaya Takehara, Teruhisa Takagishi, Kazuaki Miyamoto, Keiko Kobayashi, Masahiro Nagahama
Clostridium perfringens delta-toxin is a β-barrel-pore-forming toxin (β-PFT) and a presumptive virulence factor of type B and C strains, which are causative organisms of fatal intestinal diseases in animals. We showed previously that delta-toxin causes cytotoxicity via necrosis in sensitive cells. Here, we examined the effect of delta-toxin on intestinal membrane integrity. Delta-toxin led to a reduction in transepithelial electrical resistance (TEER) and increased the permeability of fluorescence isothiocyanate-conjugated dextran in human intestinal epithelial Caco-2 cells without changing the tight junction proteins, such as zonula occludens-1 (ZO-1), occludin, and claudin-1...
October 5, 2017: Biochimica et Biophysica Acta
https://www.readbyqxmd.com/read/28955962/vibrio-cholerae-hemolysin-the-%C3%AE-trefoil-domain-is-required-for-folding-to-the-native-conformation
#20
Amarshi Mukherjee, Sreerupa Ganguly, Nabendu S Chatterjee, Kalyan K Banerjee
Vibrio cholerae cytolysin/hemolysin (VCC) is a 65 kDa β-pore-forming toxin causing lysis and death of eukaryotic cells. Apart from the core cytolysin domain, VCC has two lectin domains with β-trefoil and β-prism folds. The β-prism domain binds to cell surface carbohydrate receptors; the role of the β-trefoil domain is unknown. Here, we show that the pro-VCC mutant without the β-trefoil domain formed aggregates highly susceptible to proteolysis, suggesting lack of a properly folded compact structure. The VCC variants with Trp532Ala or Trp534Ala mutation in the β-trefoil domain formed hemolytically inactive, protease-resistant, ring-shaped SDS-labile oligomers with diameters of ~19 nm...
December 2016: Biochemistry and Biophysics Reports
keyword
keyword
60628
1
2
Fetch more papers »
Fetching more papers... Fetching...
Read by QxMD. Sign in or create an account to discover new knowledge that matter to you.
Remove bar
Read by QxMD icon Read
×

Search Tips

Use Boolean operators: AND/OR

diabetic AND foot
diabetes OR diabetic

Exclude a word using the 'minus' sign

Virchow -triad

Use Parentheses

water AND (cup OR glass)

Add an asterisk (*) at end of a word to include word stems

Neuro* will search for Neurology, Neuroscientist, Neurological, and so on

Use quotes to search for an exact phrase

"primary prevention of cancer"
(heart or cardiac or cardio*) AND arrest -"American Heart Association"