A requirement for calcium in the transport of cobalamin across the outer membrane of Escherichia coli.

Immunogenicity of enterotoxigenic Escherichia coli outer membrane vesicles encapsulated in chitosan nanoparticles

Objective(s): Enterotoxigenic Escherichia coli (ETEC) is an important cause of diarrheal disease in humans, particularly in children under 5 years and travelers in developing countries. To our knowledge, no vaccine is licensed yet to protect against ETEC infection. Like many Gram-negative pathogens, ETEC can secrete outer membrane vesicles (OMVs). These structures contain various immunogenic vi...

SDS-PAGE Analysis of the Outer Membrane Proteins of Uropathogenic Escherichia coli Isolated from Patients in Different Wards of Nemazee Hospital, Shiraz, Iran

Background: Outer membrane proteins (OMPs) constitute the main structure and about half of the cell wall of Gram-negative bacteria. The OMPs of Escherichia coli (E. coli) play an important role in its drug resistance. Previous studies have shown that the OMPs of E. coli enhance its pathogenic effects by helping the bacterium to evade the immune defense and promote its adsorption to host cells. ...

Identification of the periplasmic cobalamin-binding protein BtuF of Escherichia coli.

Cells of Escherichia coli take up vitamin B(12) (cyano-cobalamin [CN-Cbl]) and iron chelates by use of sequential active transport processes. Transport of CN-Cbl across the outer membrane and its accumulation in the periplasm is mediated by the TonB-dependent transporter BtuB. Transport across the cytoplasmic membrane (CM) requires the BtuC and BtuD proteins, which are most related in sequence ...

The effect of calcium on the conformation of cobalamin transporter BtuB.

BtuB is a beta-barrel membrane protein that facilitates transport of cobalamin (vitamin B12) from the extracellular medium across the outer membrane of Escherichia coli. It is thought that binding of B12 to BtuB alters the conformation of its periplasm-exposed N-terminal residues (the TonB box), which enables subsequent binding of a TonB protein and leads to eventual uptake of B12 into the cyto...

A Chimeric Vaccine Consisting of Highly Immunogenic Regions form Escherichia coli Iron Regulated Outer-Membrane Proteins: An In Silico Approach