Über die Zellmembran von Escherichia Coli B

1954 ◽  
Vol 9 (6) ◽  
pp. 398-406 ◽  
Author(s):  
Wolfhard Weidel ◽  
Gebhard Koch ◽  
Friedrich Lohss
Keyword(s):  
Escherichia Coli ◽  
Chemical Analysis ◽  
Cell Membrane ◽  
B Cell ◽  
Dry Weight ◽  
Shigella Sonnei ◽  
Receptor Activity ◽  
Escherichia Coli B

Dissociation in 90% phenol uncovers a layer of the Coli B-cell membrane showing the typical antiviral specificity of the receptor for phages T3, T4 and T7. Chemical analysis proved glucose, glucosamine and a yet unknown carbohydrate, probably a heptose, to be components of the receptor material, which amounts to about 13% of the dry weight of the whole membrane.Analogous material obtained from the membrane of B/3,4,7, a B-mutant resistant against phages T3, T4 and T7, has no activity against these phages and contains glucosamine and small amounts of glucose, but no heptose.In view of similar findings of Jesaitis and Goebel with T3,4,7 - receptor material from Shigella Sonnei, the rôle of the heptose as a characteristic and functionally indispensable component of lipocarbohydrates with receptor activity against T3, T4 and T7 is discussed.

scholarly journals Modification by an R determinant for streptomycin of hissd phenotype in a mutant strain of Escherichia coli B

1968 ◽  
Vol 12 (2) ◽  
pp. 109-116 ◽  
Author(s):  
A. M. Molina ◽  
L. Calegari ◽  
G. Conte
Keyword(s):  
Escherichia Coli ◽  
Cell Membrane ◽  
Mutant Strain ◽  
Minimal Medium ◽  
Specific Requirement ◽  
Resistance Level ◽  
E Coli ◽  
Level Characteristic ◽  
Escherichia Coli B

When an R determinant for streptomycin is transferred into a conditionally streptomycin-dependent E. coli B mutant—which requires in minimal medium either histidine or streptomycin—the latter behaves like a histidineless strain. This phenotype modification shows that the repairing action of streptomycin is prevented. The specific requirement of the strain is not now replaced even by streptomycin concentrations up to 10000 µg/ml at which the conditionally streptomycin-dependent mutant could originally grow, and which are well beyond the resistance level characteristic of the R determinant itself. These data seem to suggest that a reduction in permeability of the cell membrane cannot be held responsible for the phenomenon observed.

Adrenaline inhibition of insulin release: role of the repolarization of the B cell membrane

1991 ◽  
Vol 419 (2) ◽  
pp. 131-137 ◽  
Author(s):  
Anne Debuyser ◽  
Gisela Drews ◽  
Jean Claude Henquin
Keyword(s):  
Cell Membrane ◽  
B Cell ◽  
Insulin Release

scholarly journals Role of the Lipopolysaccharide-CD14 Complex for the Activity of Hemolysin from Uropathogenic Escherichia coli

2006 ◽  
Vol 75 (2) ◽  
pp. 997-1004 ◽  
Author(s):  
Lisa E. Månsson ◽  
Peter Kjäll ◽  
Shahaireen Pellett ◽  
Gábor Nagy ◽  
Rodney A. Welch ◽  
...  
Keyword(s):  
Escherichia Coli ◽  
Cell Membrane ◽  
Signal Transduction Pathway ◽  
Recognition System ◽  
Small Gtpase ◽  
Host Cell Membrane ◽  
Common View ◽  
Experimental Artifact ◽  
Intracellular Ca

ABSTRACT Bacterial pathogens produce a variety of exotoxins, which often become associated with the bacterial outer membrane component lipopolysaccharide (LPS) during their secretion. LPS is a potent proinflammatory mediator; however, it is not known whether LPS contributes to cell signaling induced by those microbial components to which it is attached. This is partly due to the common view that LPS present in bacterial component preparations is an experimental artifact. The Escherichia coli exotoxin hemolysin (Hly) is a known inducer of proinflammatory signaling in epithelial cells, and the signal transduction pathway involves fluctuation of the intracellular-Ca2+ concentration. Since LPS is known to interact with Hly, we investigated whether it is required as a cofactor for the activity of Hly. We found that the LPS/Hly complex exploits the CD14/LPS-binding protein recognition system to bring Hly to the cell membrane, where intracellular-Ca2+ signaling is initiated via specific activation of the small GTPase RhoA. Hly-induced Ca2+ signaling was found to occur independently of the LPS receptor TLR4, suggesting that the role of LPS/CD14 is to deliver Hly to the cell membrane. In contrast, the cytolytic effect triggered by exposure of cells to high Hly concentrations occurs independently of LPS/CD14. Collectively, our data reveal a novel molecular mechanism for toxin delivery in bacterial pathogenesis, where LPS-associated microbial compounds are targeted to the host cell membrane as a consequence of their association with LPS.

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