Inhibition of ATPase activity of E. coli F1 by the water-soluble carbodiimide EDC is due to modification of several carboxyls in the .beta. subunit

Biochemistry ◽  
1984 ◽  
Vol 23 (18) ◽  
pp. 4134-4140 ◽  
Author(s):  
Hans Ruedi Lotscher ◽  
Catherina DeJong ◽  
Roderick A. Capaldi
Keyword(s):  
Atpase Activity ◽  
Water Soluble ◽  
Beta Subunit ◽  
E Coli

scholarly journals Dynamic regulation of extracellular ATP in Escherichia coli

2017 ◽  
Vol 474 (8) ◽  
pp. 1395-1416 ◽  
Author(s):  
Cora Lilia Alvarez ◽  
Gerardo Corradi ◽  
Natalia Lauri ◽  
Irene Marginedas-Freixa ◽  
María Florencia Leal Denis ◽  
...  
Keyword(s):  
Escherichia Coli ◽  
Atpase Activity ◽  
Atp Release ◽  
Membrane Vesicles ◽  
Fold Increase ◽  
Extracellular Atp ◽  
Outer Membrane Vesicles ◽  
Dynamic Regulation ◽  
E Coli

We studied the kinetics of extracellular ATP (ATPe) in Escherichia coli and their outer membrane vesicles (OMVs) stimulated with amphipatic peptides melittin (MEL) and mastoparan 7 (MST7). Real-time luminometry was used to measure ATPe kinetics, ATP release, and ATPase activity. The latter was also determined by following [32P]Pi released from [γ-32P]ATP. E. coli was studied alone, co-incubated with Caco-2 cells, or in rat jejunum segments. In E. coli, the addition of [γ-32P]ATP led to the uptake and subsequent hydrolysis of ATPe. Exposure to peptides caused an acute 3-fold (MST7) and 7-fold (MEL) increase in [ATPe]. In OMVs, ATPase activity increased linearly with [ATPe] (0.1–1 µM). Exposure to MST7 and MEL enhanced ATP release by 3–7 fold, with similar kinetics to that of bacteria. In Caco-2 cells, the addition of ATP to the apical domain led to a steep [ATPe] increase to a maximum, with subsequent ATPase activity. The addition of bacterial suspensions led to a 6–7 fold increase in [ATPe], followed by an acute decrease. In perfused jejunum segments, exposure to E. coli increased luminal ATP 2 fold. ATPe regulation of E. coli depends on the balance between ATPase activity and ATP release. This balance can be altered by OMVs, which display their own capacity to regulate ATPe. E. coli can activate ATP release from Caco-2 cells and intestinal segments, a response which in vivo might lead to intestinal release of ATP from the gut lumen.

Ribosomal protein L2 associates with E. coli HtpG and activates its ATPase activity

2010 ◽  
Vol 400 (2) ◽  
pp. 241-245 ◽  
Author(s):  
Yuko Motojima-Miyazaki ◽  
Masasuke Yoshida ◽  
Fumihiro Motojima
Keyword(s):  
Atpase Activity ◽  
Ribosomal Protein ◽  
E Coli ◽  
Ribosomal Protein L2

scholarly journals STUDY OF ANTIBACTERIAL ACTIVITY OF THE PREPARATIONS WITH DIOXIDINE AND LEVOFLOXACIN ON MAIN PURULENT-INFLAMMATORY PROCESSES PATHOGENS

2021 ◽  
Vol 74 (9) ◽  
pp. 2109-2111
Author(s):  
Evheniia A. Shtaniuk ◽  
Oleksandra O. Vovk ◽  
Larisa V. Krasnikova ◽  
Yuliia I. Polyvianna ◽  
Tetiana I. Kovalenko
Keyword(s):  
Antibacterial Activity ◽  
Water Soluble ◽  
Diffusion Method ◽  
E Coli ◽  
Mueller Hinton ◽  
Microbiological Methods ◽  
Pure Cultures ◽  
Inflammatory Processes ◽  
Definition Of

The aim: Study of antibacterial activity of the preparations, containing antiseptic dioxidine and antibiotic levofloxacin in vitro on standard strains of main optional-anaerobic pathogens of purulent-inflammatory processes of surgical wounds S. aureus, E. coli, P. aeruginosa and definition of more effective ones on them. Materials and methods: Solutions of dioxidine 1.2 %, dioxidine 1.2% with decamethaxin, Dioxisole, water soluble ointment with dioxidine 1.2% and levofloxacin 0.1% with decamethaxin were used in experiment. Antibacterial activity was studied on standard strains of S. aureus АТСС 25923, E. coli АТСС 25922, P. aeruginosa АТСС 27853. Distinguishing and identification of pure cultures of bacteria was done according to generally accepted microbiological methods. Determination of purulent-inflammatory processes pathogens sensitivity was done by disco-diffuse method on Mueller-Hinton medium. Antibacterial activity of solutions and ointments was studied with the help of agar diffusion method (“well” method) according to methodic recommendations. Each investigation was repeated 6 times. Method of variation statistics was used for the research results analysis. Results: All antibacterial preparations under study are effective and highly effective on S. aureus АТСС 25923, E. coli АТСС 25922, P. aeruginosa АТСС 27853. Solution with 1.2 % dioxidine with decamethaxin and ointment with 0.1 % levofloxacin and decamethaxin have larger growth retardation zones towards S. aureus and P. aeruginosa. E. coli strains are more sensitive to the solution of Dioxisole and ointment with 1.2 % dioxidine. Conclusions: All strains are sensitive, most of them are highly sensitive, up to 5 antibacterial preparations under study in vitro.

scholarly journals Lipid bilayer induces contraction of the denatured state ensemble of a helical-bundle membrane protein

2021 ◽  
Vol 119 (1) ◽  
pp. e2109169119
Author(s):  
Kristen A. Gaffney ◽  
Ruiqiong Guo ◽  
Michael D. Bridges ◽  
Shaima Muhammednazaar ◽  
Daoyang Chen ◽  
...  
Keyword(s):  
Membrane Protein ◽  
Lipid Bilayer ◽  
Lipid Bilayers ◽  
Limited Proteolysis ◽  
Water Soluble ◽  
Disordered Proteins ◽  
Resonance Spectroscopy ◽  
Denatured State ◽  
E Coli ◽  
State Ensemble

Defining the denatured state ensemble (DSE) and disordered proteins is essential to understanding folding, chaperone action, degradation, and translocation. As compared with water-soluble proteins, the DSE of membrane proteins is much less characterized. Here, we measure the DSE of the helical membrane protein GlpG of Escherichia coli (E. coli) in native-like lipid bilayers. The DSE was obtained using our steric trapping method, which couples denaturation of doubly biotinylated GlpG to binding of two streptavidin molecules. The helices and loops are probed using limited proteolysis and mass spectrometry, while the dimensions are determined using our paramagnetic biotin derivative and double electron–electron resonance spectroscopy. These data, along with our Upside simulations, identify the DSE as being highly dynamic, involving the topology changes and unfolding of some of the transmembrane (TM) helices. The DSE is expanded relative to the native state but only to 15 to 75% of the fully expanded condition. The degree of expansion depends on the local protein packing and the lipid composition. E. coli’s lipid bilayer promotes the association of TM helices in the DSE and, probably in general, facilitates interhelical interactions. This tendency may be the outcome of a general lipophobic effect of proteins within the cell membranes.

Evaluation of the Synergetic Effect of Water Soluble Extracts of Green Tea (Camellia sinensis) on the Activity of Ciprofloxacin in Urinary Isolated E. coli

2007 ◽  
Vol 7 (8) ◽  
pp. 1500-1503 ◽  
Author(s):  
Nima Hosseini Jazani ◽  
Minoo Zartoshti . ◽  
Shahram Shahabi . ◽  
Zahra Yekta . ◽  
Shahin Nateghi .
Keyword(s):  
Green Tea ◽  
Camellia Sinensis ◽  
Synergetic Effect ◽  
Water Soluble ◽  
E Coli ◽  
Effect Of Water

Mercury weakens membrane anchoring of Na-K-ATPase

1992 ◽  
Vol 262 (5) ◽  
pp. F837-F842 ◽  
Author(s):  
E. Imesch ◽  
M. Moosmayer ◽  
B. M. Anner
Keyword(s):  
Atpase Activity ◽  
Model Compound ◽  
Beta Subunit ◽  
Alpha Subunit ◽  
Structural Effects ◽  
Subunit Interaction ◽  
Alpha Beta ◽  
Membrane Anchoring ◽  
Atpase Inhibition

The presence of circulating inhibitors able to decrease the renal Na-K-adenosinetriphosphatase (ATPase) activity (natriuretic hormones) was postulated some 30 years ago. In the present work, the natriuretic inhibitor HgCl2 was selected as a model compound for the structural characterization of a possible natriuretic pathway for Na-K-ATPase modification. The structural effects of Na-K-ATPase inhibition by HgCl2 were assessed by trypsinolysis of the blocked enzyme in comparison with untreated preparations. The results show that inactivation of Na-K-ATPase by HgCl2 leads to the release of the alpha-subunit from the membrane preferentially in the E2 conformation but also in the E1 conformation. Apparently, HgCl2 weakens the membrane anchoring of the alpha-subunit, presumably by loosening the alpha-beta-subunit interaction. By this mechanism, the sensitivity of the Na-K-ATPase to extracellular drugs, hormones, and antibodies, as well as to intracellular proteases and other regulatory factors, could be altered.

scholarly journals Upcycling chitin-containing waste into organonitrogen chemicals via an integrated process

2020 ◽  
Vol 117 (14) ◽  
pp. 7719-7728 ◽  
Author(s):  
Xiaoqiang Ma ◽  
Gökalp Gözaydın ◽  
Huiying Yang ◽  
Wenbo Ning ◽  
Xi Han ◽  
...  
Keyword(s):  
Wide Spectrum ◽  
Value Added ◽  
Direct Conversion ◽  
Water Soluble ◽  
Integrated Biorefinery ◽  
E Coli ◽  
Shrimp Shell ◽  
Shell Waste ◽  
Shrimp Shell Waste ◽  
Value Added Products

Chitin is the most abundant renewable nitrogenous material on earth and is accessible to humans in the form of crustacean shell waste. Such waste has been severely underutilized, resulting in both resource wastage and disposal issues. Upcycling chitin-containing waste into value-added products is an attractive solution. However, the direct conversion of crustacean shell waste-derived chitin into a wide spectrum of nitrogen-containing chemicals (NCCs) is challenging via conventional catalytic processes. To address this challenge, in this study, we developed an integrated biorefinery process to upgrade shell waste-derived chitin into two aromatic NCCs that currently cannot be synthesized from chitin via any chemical process (tyrosine andl-DOPA). The process involves a pretreatment of chitin-containing shell waste and an enzymatic/fermentative bioprocess using metabolically engineeredEscherichia coli. The pretreatment step achieved an almost 100% recovery and partial depolymerization of chitin from shrimp shell waste (SSW), thereby offering water-soluble chitin hydrolysates for the downstream microbial process under mild conditions. The engineeredE. colistrains produced 0.91 g/L tyrosine or 0.41 g/Ll-DOPA from 22.5 g/L unpurified SSW-derived chitin hydrolysates, demonstrating the feasibility of upcycling renewable chitin-containing waste into value-added NCCs via this integrated biorefinery, which bypassed the Haber–Bosch process in providing a nitrogen source.

scholarly journals Enterotoxigenic Escherichia coli infection and intestinal thiamin uptake: studies with intestinal epithelial Caco-2 monolayers

2013 ◽  
Vol 305 (11) ◽  
pp. C1185-C1191 ◽  
Author(s):  
Abhisek Ghosal ◽  
Nabendu S. Chatterjee ◽  
Tristan Chou ◽  
Hamid M. Said
Keyword(s):  
Escherichia Coli ◽  
Significant Inhibition ◽  
Water Soluble ◽  
Enterotoxigenic Escherichia Coli ◽  
Adenylate Cyclase System ◽  
Mrna Levels ◽  
Intestinal Epithelial ◽  
E Coli ◽  
Heat Labile ◽  
Etec Infection

Infections with enteric pathogens like enterotoxigenic Escherichia coli ( ETEC) is a major health issue worldwide and while diarrhea is the major problem, prolonged, severe, and dual infections with multiple pathogens may also compromise the nutritional status of the infected individuals. There is almost nothing currently known about the effect of ETEC infection on intestinal absorptions of water-soluble vitamins including thiamin. We examined the effect of ETEC infection on intestinal uptake of the thiamin using as a model the human-derived intestinal epithelial Caco-2 cells. The results showed that infecting confluent Caco-2 monolayers with live ETEC (but not with boiled/killed ETEC or nonpathogenic E. coli) or treatment with bacterial culture supernatant led to a significant inhibition in thiamin uptake. This inhibition appears to be caused by a heat-labile and -secreted ETEC component and is mediated via activation of the epithelial adenylate cyclase system. The inhibition in thiamin uptake by ETEC was associated with a significant reduction in expression of human thiamin transporter-1 and -2 (hTHTR1 and hTHTR2) at the protein and mRNA levels as well as in the activity of the SLC19A2 and SLC19A3 promoters. Dual infection of Caco-2 cells with ETEC and EPEC (enteropathogenic E. coli) led to compounded inhibition in intestinal thiamin uptake. These results show for the first time that infection of human intestinal epithelial cells with ETEC causes a significant inhibition in intestinal thiamin uptake. This inhibition is mediated by a secreted heat-labile toxin and is associated with a decrease in the expression of intestinal thiamin transporters.

scholarly journals Comparison of the Compact Dry EC with the Most Probable Number Method (AOAC Official Method 966.24) for Enumeration of Escherichia coli and Coliform Bacteria in Raw Meats: Performance-Tested MethodSM 110402

2006 ◽  
Vol 89 (1) ◽  
pp. 100-114 ◽  
Author(s):  
Hidemasa Kodaka ◽  
Shingo Mizuochi ◽  
Hajime Teramura ◽  
Tadanobu Nirazuka ◽  
David Goins ◽  
...  
Keyword(s):  
Escherichia Coli ◽  
Water Soluble ◽  
Test Method ◽  
Gelling Agent ◽  
Coliform Bacteria ◽  
Most Probable Number ◽  
Official Method ◽  
Probable Number ◽  
E Coli ◽  
Raw Meats

Abstract Compact Dry E. coli/Coliform Count (EC) is a ready-to-use test method for the enumeration of Escherichia coli and coliform bacteria in food. The plates are presterilized and contain culture medium and a cold water-soluble gelling agent. The medium should be rehydrated with 1 mL diluted sample inoculated onto the center of the self-diffusible medium, allowing the solution to diffuse by capillary action. The plate can be incubated at 35C for 2024 h and the colonies counted without any further working steps. The Compact Dry EC medium plates were validated as an analysis tool for determining colony-forming units (CFU) of E. coli and coliform bacteria from a variety of raw meats using 5 different types of raw meats. The performance tests were conducted at 35C. In all studies performed, no apparent differences were observed between the Compact Dry ECmethod and theAOAC Official Method 966.24 results. For the accuracy claim (n = 75), a correlation factor of r2 = 0.93 (E. coli) and r2 = 0.93 (coliform bacteria) could be assigned, as stated in the application for Performance-Tested MethodSM.

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