Towards Computational Models of Chemotaxis in Escherichia Coli

1998 ◽  
pp. 39-45 ◽  
Author(s):  
Laurence Clark ◽  
Ray C. Paton
Keyword(s):  
Escherichia Coli ◽  
Computational Models

scholarly journals Coimmunization with Two Enterotoxigenic Escherichia coli (ETEC) Fimbrial Multiepitope Fusion Antigens Induces the Production of Neutralizing Antibodies against Five ETEC Fimbriae (F4, F5, F6, F18, and F41)

2020 ◽  
Vol 86 (24) ◽  
Author(s):  
Qiangde Duan ◽  
Wenwen Wu ◽  
Shengmei Pang ◽  
Zhiming Pan ◽  
Weiping Zhang ◽  
...  
Keyword(s):  
Escherichia Coli ◽  
Neutralizing Antibodies ◽  
Computational Models ◽  
Oral Vaccine ◽  
Enterotoxigenic Escherichia Coli ◽  
Economic Losses ◽  
Prevention Measures ◽  
Content Type ◽  
Vaccine Candidates ◽  
Postweaning Diarrhea

ABSTRACT Fimbriae mediate the initial adherence of enterotoxigenic Escherichia coli (ETEC) to the piglet small intestine and play an important role in development of ETEC-driven postweaning diarrhea (PWD). PWD inflicts huge economic losses on the swine industry each year, making development of alternative treatment and prevention measures for PWD essential. Vaccine candidates that induce antifimbria antibodies that block the initial attachment and colonization of ETEC pathogens with fimbriae are one approach that could help prevent PWD. In this study, we constructed two multiepitope fusion antigens (MEFAs) that carried, expressed, and displayed representative epitopes of F4, F5, F6, F18, and F41 ETEC fimbriae. These MEFAs used either the F4 major subunit FaeG or the F18 adhesive subunit FedF as a backbone. To assess the potential of these MEFAs as antifimbria vaccine candidates that could help prevent PWD, we generated computational models of the MEFAs, constructed them, and then tested their immunogenicity by using them to immunize mice. Computational modeling showed that all relevant epitopes were exposed on the MEFA surface. We found that coadministration of our MEFAs in mice successfully induced five fimbria-specific antibodies in accordance with the epitopes included in the MEFA constructs. Furthermore, the induced antibodies can significantly inhibit the ability of ETEC strains that express F4, F5, F6, F18, and F41 fimbriae to adhere to piglet small intestinal IPEC-1 and IPEC-J2 cells. Our findings indicate that the antifimbria antibodies induced by our FaeG-Fim41a-FanC-FasA and FedF-FasA-Fim41a-FanC fimbria MEFAs blocked adherence of five ETEC fimbriae, suggesting these multivalent fimbria MEFAs may be useful for developing broadly protective antifimbria vaccines against PWD caused by ETEC infections. IMPORTANCE Enterotoxigenic Escherichia coli (ETEC)-associated postweaning diarrhea (PWD) is still a leading disease in recently weaned piglets. Vaccination is considered to be the most ideal and efficacious strategy for preventing PWD. Recently, a commercialized live monovalent F4 oral vaccine and a bivalent F4/F18 oral vaccine have been demonstrated to effectively protect piglets in the F4-positive (F4+) and F18+ ETEC challenge models. However, they will not provide cross-protection against F5+, F6+, or F41+ ETEC-associated PWD cases, as they lack all five fimbria antigens. Thus, a multivalent vaccine containing all five ETEC fimbriae would be more effective in preventing ETEC-driven PWD. In this study, we designed two fimbria-targeted MEFAs using the MEFA technology, and further study demonstrated that these coadministered MEFAs in mice can induce protective antibodies against the five fimbriae expressed by ETEC. These MEFAs could be used as an efficient PWD vaccine candidate; furthermore, MEFA-based structural technology provides an alternative and promising strategy for the development of vaccines against pathogens with heterogeneous virulence factors.

Structural organization of escherichia coli ribosomes as determined by immuno electron microscopy

1978 ◽  
Vol 36 (2) ◽  
pp. 166-167 ◽  
Author(s):  
G. Stöffler ◽  
R.W. Bald ◽  
J. Dieckhoff ◽  
H. Eckhard ◽  
R. Lührmann ◽  
...  
Keyword(s):  
Electron Microscopy ◽  
Escherichia Coli ◽  
Ribosomal Proteins ◽  
Structural Organization ◽  
Three Dimensional ◽  
Ribosomal Subunit ◽  
Spatial Arrangement ◽  
Small Subunit ◽  
Antibody Binding ◽  
Immuno Electron Microscopy

A central step towards an understanding of the structure and function of the Escherichia coli ribosome, a large multicomponent assembly, is the elucidation of the spatial arrangement of its 54 proteins and its three rRNA molecules. The structural organization of ribosomal components has been investigated by a number of experimental approaches. Specific antibodies directed against each of the 54 ribosomal proteins of Escherichia coli have been performed to examine antibody-subunit complexes by electron microscopy. The position of the bound antibody, specific for a particular protein, can be determined; it indicates the location of the corresponding protein on the ribosomal surface.The three-dimensional distribution of each of the 21 small subunit proteins on the ribosomal surface has been determined by immuno electron microscopy: the 21 proteins have been found exposed with altogether 43 antibody binding sites. Each one of 12 proteins showed antibody binding at remote positions on the subunit surface, indicating highly extended conformations of the proteins concerned within the 30S ribosomal subunit; the remaining proteins are, however, not necessarily globular in shape (Fig. 1).

Sites of Adsorption of the Bacteriophages T3 and T5 on the Wall of Escherichia Coli B.

1967 ◽  
Vol 25 ◽  
pp. 96-97
Author(s):  
Manfred E. Bayer
Keyword(s):  
Escherichia Coli ◽  
Cell Wall ◽  
Electron Microscope ◽  
Uranyl Acetate ◽  
E Coli ◽  
Receptor Sites ◽  
Rigid Cell Wall ◽  
Host Cell Surface ◽  
Bacterial Viruses ◽  
Escherichia Coli B

Bacterial viruses adsorb specifically to receptors on the host cell surface. Although the chemical composition of some of the cell wall receptors for bacteriophages of the T-series has been described and the number of receptor sites has been estimated to be 150 to 300 per E. coli cell, the localization of the sites on the bacterial wall has been unknown.When logarithmically growing cells of E. coli are transferred into a medium containing 20% sucrose, the cells plasmolize: the protoplast shrinks and becomes separated from the somewhat rigid cell wall. When these cells are fixed in 8% Formaldehyde, post-fixed in OsO4/uranyl acetate, embedded in Vestopal W, then cut in an ultramicrotome and observed with the electron microscope, the separation of protoplast and wall becomes clearly visible, (Fig. 1, 2). At a number of locations however, the protoplasmic membrane adheres to the wall even under the considerable pull of the shrinking protoplast. Thus numerous connecting bridges are maintained between protoplast and cell wall. Estimations of the total number of such wall/membrane associations yield a number of about 300 per cell.

Infection of Escherichia coli with bacteriophages

1969 ◽  
Vol 27 ◽  
pp. 370-371
Author(s):  
Manfred E. Bayer
Keyword(s):  
Escherichia Coli ◽  
Nucleic Acid ◽  
Cell Surface ◽  
Virus Type ◽  
Infection Process ◽  
Adsorption Site ◽  
The Other ◽  
Specific Receptors ◽  
Bacterial Receptors

The first step in the infection of a bacterium by a virus consists of a collision between cell and bacteriophage. The presence of virus-specific receptors on the cell surface will trigger a number of events leading eventually to release of the phage nucleic acid. The execution of the various "steps" in the infection process varies from one virus-type to the other, depending on the anatomy of the virus. Small viruses like ØX 174 and MS2 adsorb directly with their capsid to the bacterial receptors, while other phages possess attachment organelles of varying complexity. In bacteriophages T3 (Fig. 1) and T7 the small conical processes of their heads point toward the adsorption site; a welldefined baseplate is attached to the head of P22; heads without baseplates are not infective.

The Nature of the Intramembrane Particle

1980 ◽  
Vol 38 ◽  
pp. 688-691
Author(s):  
A.J. Verkleij
Keyword(s):  
Escherichia Coli ◽  
Tight Junction ◽  
Gap Junction ◽  
The Other ◽  
Fracture Face ◽  
Band 3 Protein ◽  
Satisfactory Explanation ◽  
Freeze Fracturing ◽  
Intramembrane Particle ◽  
Luminal Membrane

Freeze-fracturing splits membranes into two helves, thus allowing an examination of the membrane interior. The 5-10 rm particles visible on both monolayers are widely assumed to be proteinaceous in nature. Most membranes do not reveal impressions complementary to particles on the opposite fracture face, if the membranes are fractured under conditions without etching. Even if it is considered that shadowing, contamination or fracturing itself might obscure complementary pits', there is no satisfactory explanation why under similar physical circimstances matching halves of other membranes can be visualized. A prominent example of uncomplementarity is found in the erythrocyte manbrane. It is wall established that band 3 protein and possibly glycophorin represents these nonccmplanentary particles. On the other hand a number of membrane types show pits opposite the particles. Scme well known examples are the ";gap junction',"; tight junction, the luminal membrane of the bladder epithelial cells and the outer membrane of Escherichia coli.

Cell division is required for resolution of dimer chromosomes at the dif locus of Escherichia coli

1998 ◽  
Vol 27 (2) ◽  
pp. 257-268 ◽  
Author(s):  
Walter W. Steiner ◽  
Peter L. Kuempel
Keyword(s):  
Escherichia Coli ◽  
Cell Division

Contributions of the substrate-binding arginine residues to maleate-induced closure of the active site of Escherichia coli aspartate aminotransferase

2001 ◽  
Vol 268 (6) ◽  
pp. 1640-1645
Author(s):  
Annelise Matharu ◽  
Hideyuki Hayashi ◽  
Hiroyuki Kagamiyama ◽  
Bruno Maras ◽  
Robert A. John
Keyword(s):  
Escherichia Coli ◽  
Active Site ◽  
Aspartate Aminotransferase ◽  
Substrate Binding ◽  
Arginine Residues

Structural and functional properties of Escherichia coli-derived nucleoplasmin A comparative study of recombinant and natural proteins

2001 ◽  
Vol 268 (6) ◽  
pp. 1739-1748
Author(s):  
Aitor Hierro ◽  
Jesus M. Arizmendi ◽  
Javier De Las Rivas ◽  
M. Angeles Urbaneja ◽  
Adelina Prado ◽  
...  
Keyword(s):  
Escherichia Coli ◽  
Comparative Study ◽  
Functional Properties ◽  
Structural And Functional Properties
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