Studies on the Protein Moiety of Endotoxin from Gram-Negative Bacteria: Characterization of the Protein Moiety Isolated by Phenol Treatment of Endotoxin from S. marcescens 08 and E. coli O 141:K85(B)

1970 ◽  
Author(s):  
W. Wober ◽  
P. Alaupovic
Keyword(s):  
Gram Negative Bacteria ◽  
Gram Negative ◽  
E Coli ◽  
Phenol Treatment ◽  
Protein Moiety

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 Characterization of the β-lactamase specified by the resistance factor R-1818 in Escherichia coli K12 and other Gram-negative bacteria

1971 ◽  
Vol 123 (4) ◽  
pp. 501-505 ◽  
Author(s):  
J. W. Dale
Keyword(s):  
Escherichia Coli ◽  
Host Species ◽  
Host Bacterium ◽  
Gram Negative Bacteria ◽  
Gram Negative ◽  
E Coli ◽  
R Factor ◽  
Relationship Of ◽  
The Relationship

1. The amino acid composition of the β-lactamase from E. coli (R-1818) was determined. 2. The R-1818 β-lactamase is inhibited by formaldehyde, hydroxylamine, sodium azide, iodoacetamide, iodine and sodium chloride. 3. The Km values for benzylpenicillin, ampicillin and oxacillin have been determined by using the R-factor enzyme from different host species. The same values were obtained, irrespective of the host bacterium. 4. The molecular weight of the enzyme was found to be 44600, and was the same for all host species. 5. The relationship of R-1818 and R-GN238 β-lactamases is discussed.

Synthesis, Characterization, and Antibacterial Evaluation of Curcumin-Sulfanilamide Compound

2020 ◽  
Vol 840 ◽  
pp. 265-269
Author(s):  
Nurjanah Nurjanah ◽  
Endang Saepudin
Keyword(s):  
Antibacterial Activity ◽  
Functional Group ◽  
Biological Activities ◽  
Curcuma Longa ◽  
Gram Negative Bacteria ◽  
Gram Negative ◽  
E Coli ◽  
Gram Positive Bacteria ◽  
Ftir Spectrophotometry

Curcumin, a diarylheptanoids compound which isolated primary from Curcuma longa, exhibits a variety of exciting biological activities, including as an antibacterial agent. In the present study, a sulfanilamide-contained curcumin compound was synthesized and characterized to investigate the antibacterial activity against gram-positive bacteria S. aureus, B. subtilis and gram-negative bacteria E. coli. The characterization of the synthesized compound was determined by analysing peak absorbance, functional group, and molecular weight using mass spectroscopy, UV/Vis and FTIR spectrophotometry. Curcumin-sulfanilamide compound exhibited the best antibacterial activity against gram-negative bacteria compared to curcumin and the curcumin-derived compound containing isoxazole with inhibitory zone of 11 mm.

scholarly journals Functional and structural characterization of Serratia marcescens ExbB: determinants of the interaction with HasB/TonB

2021 ◽  
Author(s):  
Valérie Biou ◽  
Ricardo Jorge D Adaixo ◽  
Mohamed Chami ◽  
Pierre-Damien Coureux ◽  
Benoist Laurent ◽  
...  
Keyword(s):  
Serratia Marcescens ◽  
Molecular Motor ◽  
Opportunistic Pathogen ◽  
Gram Negative Bacteria ◽  
Gram Negative ◽  
E Coli ◽  
New Class ◽  
Heme Acquisition ◽  
Shed Light

ExbBD is part of a cytoplasmic membrane molecular motor driven by the proton-motive force. It belongs to the larger family of motors involved in nutriment import across the outer membrane of Gram-negative bacteria (ExbBD), flagellar rotation (MotAB) or late steps of cell division in Gram-negative bacteria (TolQR). ExbB and ExbD are integral membrane proteins with three (ExbB) or one (ExbD) transmembrane segment. Here we have solved by single-particle cryo-EM the structures of ExbB alone and of the ExbB-ExbD complex of the opportunistic pathogen Serratia marcescens. ExbBSm alone behaves as a stable pentamer, and the complex displays the ExbB5-ExbD2 stoichiometry. This is similar to what has been observed for ExbB-ExbD complexes from Escherichia coli and Pseudomonas savastanoi as well as MotAB complexes from various species. We identified residues located in the first TM of ExbBSm and ExbBEc that are likely involved in the interaction with TonB/HasB and that are essential for function. ExbBSm has a ca. 40 residues long periplasmic extension absent in E. coli. Such long ExbBs are found in some Gammaproteobacteria, and several genera of Alphaproteobacteria. We show that this extension interacts with HasB, a dedicated TonB paralog from the heme acquisition system (Has) from S. marcescens. We also show that it is involved in heme acquisition via the Has system from S. marcescens. ExbBSm represents thus a new class of ExbB protein and our results shed light on the specificity determinants between the ExbB-ExbD complex and their associated TonB partners.

scholarly journals Evaluation the Biological Activity of Nano- Gentamicin Prepared and Characterization of Nanoparticles

2021 ◽  
Vol 8 (2) ◽  
pp. 84-90
Author(s):  
Rana Kamal ◽  
Quraish A. Kahdhum ◽  
Awatif I. Mohammed ◽  
Ahmed J. Essa ◽  
Maan A. Abd Elhamid ◽  
...  
Keyword(s):  
Biological Activity ◽  
Antibacterial Effect ◽  
Sol Gel ◽  
Homogeneous Distribution ◽  
Gram Negative Bacteria ◽  
Gram Positive ◽  
Gram Negative ◽  
E Coli ◽  
Average Size

Gentamycin is a broad-spectrum antibacterial against Gram-positive and Gram-negative bacteria. Gentamycin Sulfate is a white powder that is freely soluble in water and insoluble in alcohol, acetone, chloroform and ether. The study aims to determine the characterization and the biological activity of gentamicin in the Nano-form prepared by Sol-gel application using an ultrasound device by aqueous solution at temperature of 80°. Nano gentamycin examined by Scanning electron microscopy (SEM), transmission (TEM) and the antibacterial effect test of both Nano and stander gentamycin were analyzed. The results showing that the average size of gentamycin nanoparticles is 68.51 nanometers with homogeneous distribution. The antibacterial effect of Nano gentamycin take a wide inhibition range of Gram-positive and Gram-negative bacteria compared to the standard substance, the inhibition diameters are for E. coli (29 mm) and for St. epidermidis (27 mm). In the other side the inhibitory ability for standard gentamicin for St. epidrmidis and E. coli were 18 mm and 20 mm, respectively.

scholarly journals PREVALENCE AND MOLECULAR CHARACTERIZATION OF blaCTX-M-15-PRODUCING PATHOGENIC GRAM-NEGATIVE BACTERIA FROM VARIOUS CLINICAL SAMPLES

2018 ◽  
Vol 11 (10) ◽  
pp. 386
Author(s):  
Sindhuja S ◽  
Sureshkumar Bt ◽  
Janaki S ◽  
Thenmozhi S
Keyword(s):  
Molecular Characterization ◽  
Pathogenic Bacteria ◽  
Disk Diffusion ◽  
Diffusion Method ◽  
Clinical Samples ◽  
Gram Negative Bacteria ◽  
Gram Negative ◽  
E Coli

Objective: The objective of this study was to describe the prevalence and molecular characterization of blaCTX-M-15-producing pathogenic Gram-negative bacteria from various clinical samples isolated from clinically suspected patients.Methods: In this study, clinical samples of urine, stool, sputum, and pus were collected from 244 patients with nosocomial infections. The phenotypic identification of extended-spectrum β-lactamases (ESBL) was confirmed by double-disk synergy test and combined disk diffusion test. In vitro, the susceptibility pattern of antimicrobial agents against pathogenic isolates was performed by Kirby–Bauer disk diffusion method. The identification of blaCTX-M-15-producing Escherichia coli was assessed by polymerase chain reaction method.Results: The frequency of ESBL-producing pathogenic bacteria from screened was 6 (46.15%). In vitro, susceptibility to pathogenic bacteria showed that the majority of isolates were highly susceptible to amoxicillin-clavulanic acid (97.87%), ofloxacin (93.33%), and Pseudomonas aeruginosa showed 100% sensitive to ceftazidime, cefotaxime, cefixime, cefoperazone, and meropenem (92.30%). The rates of resistance to other antibiotics varied from <26.66%. Among six tested isolates, only one E. coli isolates showed blaCTX-M-15 gene.Conclusion: Due to the increase of E. coli with multiple ESBL genes, continuous surveillance should be needed in clinical field to use of appropriate antibiotics and the control of infections.

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