scholarly journals Characterization of a porin channel in the endosymbiont of the trypanosomatid protozoan Crithidia deanei

Microbiology ◽  
2011 ◽  
Vol 157 (10) ◽  
pp. 2818-2830 ◽  
Author(s):  
Iamara da Silva Andrade ◽  
João Lídio Vianez-Júnior ◽  
Carolina Lage Goulart ◽  
Fabrice Homblé ◽  
Jean-Marie Ruysschaert ◽  
...  
Keyword(s):  
3D Structure ◽  
Symbiotic Bacterium ◽  
Gram Negative Bacteria ◽  
Genome Database ◽  
Gram Negative ◽  
Secondary Structure Analysis ◽  
Electrophysiological Measurements ◽  
Mutualistic Relationship ◽  
Obligate Intracellular Bacteria

Crithidia deanei is a trypanosomatid protozoan that harbours a symbiotic bacterium. The partners maintain a mutualistic relationship, thus constituting an excellent model for studying metabolic exchanges between the host and the symbiont, the origin of organelles and cellular evolution. According to molecular analysis, symbionts of different trypanosomatid species share high identity and descend from a common ancestor, a β-proteobacterium of the genus Bordetella. The endosymbiont is surrounded by two membranes, like Gram-negative bacteria, but its envelope presents special features, since phosphatidylcholine is a major membrane component and the peptidoglycan layer is highly reduced, as described in other obligate intracellular bacteria. Like the process that generated mitochondria and plastids, the endosymbiosis in trypanosomatids depends on pathways that facilitate the intensive metabolic exchanges between the bacterium and the host protozoan. A search of the annotated symbiont genome database identified one sequence with identity to porin-encoding genes of the genus Bordetella. Considering that the symbiont outer membrane has a great accessibility to cytoplasm host factors, it was important to characterize this single porin-like protein using biochemical, molecular, computational and ultrastructural approaches. Antiserum against the recombinant porin-like molecule revealed that it is mainly located in the symbiont envelope. Secondary structure analysis and comparative modelling predicted the protein 3D structure as an 18-domain β-barrel, which is consistent with porin channels. Electrophysiological measurements showed that the porin displays a slight preference for cations over anions. Taken together, the data presented herein suggest that the C. deanei endosymbiont porin is phylogenetically and structurally similar to those described in Gram-negative bacteria, representing a diffusion channel that might contribute to the exchange of nutrients and metabolic precursors between the symbiont and its host cell.

Electrophysiological Characterization of Transport Across Outer Membrane Channels from Gram-Negative Bacteria in Their Native Environment

2019 ◽  
Author(s):  
Jiajun Wang ◽  
Rémi Terrasse ◽  
Jayesh Arun Bafna ◽  
Lorraine Benier ◽  
Mathias Winterhalter
Keyword(s):  
Outer Membrane ◽  
Lipid Membrane ◽  
Membrane Vesicles ◽  
Outer Membrane Vesicles ◽  
Multi Drug Resistance ◽  
Gram Negative Bacteria ◽  
Membrane Channels ◽  
Gram Negative ◽  
Electrophysiological Characterization

Multi-drug resistance in Gram-negative bacteria is often associated with low permeability of the outer membrane. To investigate the role of membrane channels in the uptake of antibiotics, we extract, purify and reconstitute them into artificial planar membranes. To avoid this time-consuming procedure, here we show a robust approach using fusion of native outer membrane vesicles (OMV) into planar lipid bilayer which moreover allows also to some extend the characterization of membrane protein channels in their native environment. Two major membrane channels from <i>Escherichia coli</i>, OmpF and OmpC, were overexpressed from the host and the corresponding OMVs were collected. Each OMV fusion revealed surprisingly single or only few channel activities. The asymmetry of the OMV´s translates after fusion into the lipid membrane with the LPS dominantly present at the side of OMV addition. Compared to conventional reconstitution methods, the channels fused from OMVs containing LPS have similar conductance but a much broader distribution. The addition of Enrofloxacin on the LPS side yields somewhat higher association (<i>k<sub>on</sub></i>) and lower dissociation (<i>k<sub>off</sub></i>) rates compared to LPS-free reconstitution. We conclude that using outer membrane vesicles is a fast and easy approach for functional and structural studies of membrane channels in the native membrane.

scholarly journals Discovery and Characterization of the Antimetabolite Action of Thioacetamide-Linked 1,2,3-Triazoles as Disruptors of Cysteine Biosynthesis in Gram-Negative Bacteria

2019 ◽  
Vol 6 (3) ◽  
pp. 467-478 ◽  
Author(s):  
Miranda J. Wallace ◽  
Suresh Dharuman ◽  
Dinesh M. Fernando ◽  
Stephanie M. Reeve ◽  
Clifford T. Gee ◽  
...  
Keyword(s):  
Gram Negative Bacteria ◽  
Cysteine Biosynthesis ◽  
Gram Negative

Protein expression and extraction of hard-to-produce proteins in the periplasmic space of Escherichia coli v1

2021 ◽  
Author(s):  
Cristina Hernandez Rollan ◽  
Kristoffer Bach Falkenberg ◽  
Maja Rennig ◽  
Andreas Birk Bertelsen ◽  
Morten Norholm
Keyword(s):  
Protein Production ◽  
Expression System ◽  
Gram Negative Bacteria ◽  
Gram Negative ◽  
E Coli ◽  
New Family ◽  
Lytic Polysaccharide Monooxygenases ◽  
Strain Bl21 ◽  
Polysaccharide Monooxygenases

E. coli is a gram-negative bacteria used mainly in academia and in some industrial scenarios, as a protein production workhorse. This is due to its ease of manipulation and the range of genetic tools available. This protocol describes how to express proteins in the periplasm E. coli with the strain BL21 (DE3) using a T7 expression system. Specifically, it describes a series of steps and tips to express "hard-to-express" proteins in E. coli, as for instance, LPMOs. The protocol is adapted from Hemsworth, G. R., Henrissat, B., Davies, G. J., and Walton, P. H. (2014) Discovery and characterization of a new family of lytic polysaccharide monooxygenases. Nat. Chem. Biol.10, 122–126. .

scholarly journals SKRENING BAKTERI TOLERAN PESTISIDA DENGAN BAHAN AKTIF KLORANTRANILIPROL ASAL TANAH PERTANIAN BATURITI TABANAN BALI

2017 ◽  
Vol 21 (1) ◽  
pp. 1
Author(s):  
NI KADEK WIWIK SINTA DEWI ◽  
IDA BAGUS GEDE DARMAYASA ◽  
I KETUT SUNDRA
Keyword(s):  
Large Scale ◽  
Chemical Compounds ◽  
Mineral Medium ◽  
Gram Negative Bacteria ◽  
Soil Mineral ◽  
Gram Negative ◽  
Gram Positive Bacteria ◽  
Numerous Problem ◽  
Stage 1

In Indonesia agriculture practice often used the large scale pesticide application such as insecticide, herbicide, and fungicide. The wide use of toxic pesticide has created numerous problem in increasing environtmental hazard to human and to other animals. Many of soil bacteria had important role to degrading chemical compounds into simpler compounds as a bioremediation agent. The aim of this study was to screen the Chlorantraniliprole tolerant bacteria using soil mineral medium with Prevathon pesticide addition, also teo identificate the species of bacteria. This research was conducted at Microbiology Laboratory, Faculty of Mathematics and Natural Sciences, Udayana University. The research was done in three analysis, (1) bacteria test on Prevathon pesticide addition to mineral medium treatment, (2) characterization of bacteria, (3) Identification of pesticide tolerant bacteria with BD BBL Crystal Enteric/Non FermenterID Kit. The results showed that mineral medium with the addition of pesticides Prevathon treatment able to provide a significant different effect on the enrichment stage 1, stage 2 and stage 3 (P<0.05), there was 5 isolates pesticide tolerant bacteria that isolated from Baturiti Tabanan cultivated soil that was BSP 1, BSP 2, BSP 3 known as gram negative bacteria, and BSP 4, BSP 5 known as Gram positive bacteria, pesticide tolerant bacteria identified as Serratia marcescens which is a Gram negative bacteria group and may cause pathogenic.

scholarly journals Characterization of Certain Gram-Negative Bacteria from Surface Waters1

1965 ◽  
Vol 13 (4) ◽  
pp. 575-578 ◽  
Author(s):  
A. W. Hoadley ◽  
Elizabeth McCoy
Keyword(s):  
Gram Negative Bacteria ◽  
Gram Negative

scholarly journals A g-Type Lysozyme from Deep-Sea Hydrothermal Vent Shrimp Kills Selectively Gram-Negative Bacteria

Molecules ◽  
2021 ◽  
Vol 26 (24) ◽  
pp. 7624
Author(s):  
Jing-Chang Luo ◽  
Jian Zhang ◽  
Li Sun
Keyword(s):  
Deep Sea ◽  
Hydrothermal Vent ◽  
Binding Capacity ◽  
Cellular Membrane ◽  
Structural Features ◽  
Gram Negative Bacteria ◽  
Gram Negative ◽  
Bacterial Binding ◽  
Muramidase Activity

Lysozyme is a key effector molecule of the innate immune system in both vertebrate and invertebrate. It is classified into six types, one of which is the goose-type (g-type). To date, no study on g-type lysozyme in crustacean has been documented. Here, we report the identification and characterization of a g-type lysozyme (named LysG1) from the shrimp inhabiting a deep-sea hydrothermal vent in Manus Basin. LysG1 possesses conserved structural features of g-type lysozymes. The recombinant LysG1 (rLysG1) exhibited no muramidase activity and killed selectively Gram-negative bacteria in a manner that depended on temperature, pH, and metal ions. rLysG1 bound target bacteria via interaction with bacterial cell wall components, notably lipopolysaccharide (LPS), and induced cellular membrane permeabilization, which eventually caused cell lysis. The endotoxin-binding capacity enabled rLysG1 to alleviate the inflammatory response induced by LPS. Mutation analysis showed that the bacterial binding and killing activities of rLysG1 required the integrity of the conserved α3 and 4 helixes of the protein. Together, these results provide the first insight into the activity and working mechanism of g-type lysozyme in crustacean and deep-sea organisms.

Synthesis and Characterization of Cadmium with Titanium Oxide (Cd-TiO2) Nanocomposite: Testing its Antibacterial Effect

2021 ◽  
Vol 12 (4) ◽  
pp. 2523-2529
Author(s):  
Daniel Sam N ◽  
Anish C I ◽  
Sabeena G ◽  
Rajaduraipandian S ◽  
Manobala ◽  
...  
Keyword(s):  
Sol Gel ◽  
Gram Negative Bacteria ◽  
X Ray Diffraction ◽  
Sem Images ◽  
Gram Negative ◽  
X Ray ◽  
Weight Percentage ◽  
Inhibition Concentration ◽  
Xrd Patterns

Sol gel methods were used for the study of the antimicrobial activity of Cd-TiO2 against gram-negative and positive bacteria. These Cd-TiO2 have been characterized by various optical and techniques. They have been exhibited by X-ray diffraction, scanning electron microscopy, ultraviolet spectroscopy, and infrared spectroscopy. The structures of the various XRD patterns indicate that the product has a structure. The particle size of Cd-TiO2 is 35nm. The SEM images confirm the spherical appearance of the sample. The energy X-ray spectra have been confirmed as well and then C, O, Ti, Cd, Pt element are present in Cd-TiO2. The weight percentage of Cadmium is 5.8%, Ti is 51.03%, C is 5.13% and O is 31.75% in Cd-TiO2. BET image shows that the major pore size distribution of Cd-TiO2 is ranged from 2.24 nm. The Cd-TiO2 that the antibacterial activity when tested against the pathogens only gram-negative bacteria such as Pseudomonas. The zone of minimum inhibition concentration was measured in a range of 20mm in 25μl and 30mm in 100μl.

Sign in / Sign up

Export Citation Format

Share Document