Chapter 7. Studies on type 1-fimbriated bacteria to understand and combat bacterial adhesion

2012 ◽  
pp. 194-207 ◽  
Author(s):  
Thisbe K. Lindhorst
Keyword(s):  
Bacterial Adhesion

scholarly journals Are D-manno-configured Amadori products ligands of the bacterial lectin FimH?

2015 ◽  
Vol 11 ◽  
pp. 1096-1104 ◽  
Author(s):  
Tobias-Elias Gloe ◽  
Insa Stamer ◽  
Cornelia Hojnik ◽  
Tanja M Wrodnigg ◽  
Thisbe K Lindhorst
Keyword(s):  
Molecular Docking ◽  
Binding Site ◽  
Bacterial Adhesion ◽  
Carbohydrate Binding ◽  
Amadori Products ◽  
E Coli ◽  
Type D ◽  
Amadori Rearrangement ◽  
Carbohydrate Binding Site

The Amadori rearrangement was employed for the synthesis ofC-glycosyl-type D-mannoside analogues, namely 1-propargylamino- and 1-phenylamino-1-deoxy-α-D-manno-heptopyranose. They were investigated as ligands of type 1-fimbriatedE. colibacteria by means of molecular docking and bacterial adhesion studies. It turns out that Amadori rearrangement products have a limited activity as inhibitors of bacterial adhesion because the β-C-glycosidically linked aglycone considerably hampers complexation within the carbohydrate binding site of the type 1-fimbrial lectin FimH.

Trivalent Cluster Mannosides with Aromatic Partial Structure as Ligands for the Type 1 Fimbrial Lectin of Escherichia coli

2002 ◽  
Vol 55 (2) ◽  
pp. 87 ◽  
Author(s):  
N. Röckendorf ◽  
O. Sperling ◽  
T. K. Lindhorst
Keyword(s):  
Bacterial Adhesion ◽  
Host Cells ◽  
Carbohydrate Binding ◽  
Partial Structure ◽  
E Coli ◽  
Type 1 Fimbriae ◽  
Chaperone Protein ◽  
Clustering Approach ◽  
Carbohydrate Binding Site

Mannose-specific adhesion of E. coli bacteria to their host cells is mediated by so-called type 1 fimbriae containing lectin domains present on the type 1 fimbrial FimH protein. The crystal structure of a FimH-FimC(chaperone) protein complex revealed a number of amino acids in the carbohydrate binding site with aromatic side chains. This finding is in keeping with earlier results showing high inhibitory potencies of aryl mannosides when tested as inhibitors of type 1 fimbriae-mediated bacterial adhesion. In addition, clustering of mannosyl moieties also led to favourable effects, as in the case of trivalent cluster mannosides such as (1). In order to combine both, i.e. the clustering approach and the advantage of an aromatic moiety, the herein presented study has emphasized the synthesis of three cluster mannosides (2), (3), and (4), as ligands for the type 1 fimbrial lectin, which contain a phenyl partial structure in different proximity to the core of the molecule. The inhibitory potencies of the new cluster mannosides were determined in enzyme-linked immunosorbent assays (ELISAs).

scholarly journals Synthesis and testing of the first azobenzene mannobioside as photoswitchable ligand for the bacterial lectin FimH

2013 ◽  
Vol 9 ◽  
pp. 223-233 ◽  
Author(s):  
Vijayanand Chandrasekaran ◽  
Katharina Kolbe ◽  
Femke Beiroth ◽  
Thisbe K Lindhorst
Keyword(s):  
Bacterial Adhesion ◽  
Water Solubility ◽  
Docking Studies ◽  
Solid Support ◽  
Photochromic Properties ◽  
Inhibitory Potency ◽  
E Coli ◽  
Type 1 Fimbriae ◽  
Computer Aided

In order to allow spatial and temporal control of carbohydrate-specific bacterial adhesion, it has become our goal to synthesise azobenzene mannosides as photoswitchable inhibitors of type 1 fimbriae-mediated adhesion of E. coli. An azobenzene mannobioside 2 was prepared and its photochromic properties were investigated. The E→Z isomerisation was found to be highly effective, yielding a long-lived (Z)-isomer. Both isomers, E and Z, show excellent water solubility and were tested as inhibitors of mannoside-specific bacterial adhesion in solution. Their inhibitory potency was found to be equal and almost two orders of magnitude higher than that of the standard inhibitor methyl mannoside. These findings could be rationalised on the basis of computer-aided docking studies. The properties of the new azobenzene mannobioside have qualified this glycoside to be eventually employed on solid support, in order to fabricate photoswitchable adhesive surfaces.

Crystalloid Inclusions in Hepatocyte Mitochondria and Their Similarity to Cytoplasmic Crystalloids

1974 ◽  
Vol 32 ◽  
pp. 198-199
Author(s):  
Odell T. Minick ◽  
Hidejiro Yokoo
Keyword(s):  
Liver Disease ◽  
Alcoholic Liver Disease ◽  
Special Interest ◽  
Structural Variations ◽  
Mitochondrial Alterations ◽  
The Matrix ◽  
Crystalloid Inclusions ◽  
Liver Biopsies

Mitochondrial alterations were studied in 25 liver biopsies from patients with alcoholic liver disease. Of special interest were the morphologic resemblance of certain fine structural variations in mitochondria and crystalloid inclusions. Four types of alterations within mitochondria were found that seemed to relate to cytoplasmic crystalloids.Type 1 alteration consisted of localized groups of cristae, usually oriented in the long direction of the organelle (Fig. 1A). In this plane they appeared serrated at the periphery with blind endings in the matrix. Other sections revealed a system of equally-spaced diagonal lines lengthwise in the mitochondrion with cristae protruding from both ends (Fig. 1B). Profiles of this inclusion were not unlike tangential cuts of a crystalloid structure frequently seen in enlarged mitochondria described below.

Evidence for a shear mechanism for the precipitation of γ-zirconium hydride in zirconium

1978 ◽  
Vol 36 (1) ◽  
pp. 658-659
Author(s):  
G.J.C. Carpenter
Keyword(s):  
Elevated Temperature ◽  
Strain Field ◽  
Zirconium Hydride ◽  
Zirconium Atom ◽  
Atom Diffusion ◽  
Solvus Temperature ◽  
Hexagonal Close Packed ◽  
Partial Dislocations ◽  
The Face

In zirconium-hydrogen alloys, rapid cooling from an elevated temperature causes precipitation of the face-centred tetragonal (fct) phase, γZrH, in the form of needles, parallel to the close-packed <1120>zr directions (1). With low hydrogen concentrations, the hydride solvus is sufficiently low that zirconium atom diffusion cannot occur. For example, with 6 μg/g hydrogen, the solvus temperature is approximately 370 K (2), at which only the hydrogen diffuses readily. Shears are therefore necessary to produce the crystallographic transformation from hexagonal close-packed (hep) zirconium to fct hydride.The simplest mechanism for the transformation is the passage of Shockley partial dislocations having Burgers vectors (b) of the type 1/3<0110> on every second (0001)Zr plane. If the partial dislocations are in the form of loops with the same b, the crosssection of a hydride precipitate will be as shown in fig.1. A consequence of this type of transformation is that a cumulative shear, S, is produced that leads to a strain field in the surrounding zirconium matrix, as illustrated in fig.2a.

Direct structure images of 30° partial dislocation cores in silicon

1987 ◽  
Vol 45 ◽  
pp. 242-243
Author(s):  
J. C. Barry ◽  
H. Alexander
Keyword(s):  
Dislocation Core ◽  
Preparation Technique ◽  
Burgers Vector ◽  
Vector Type ◽  
Sample Preparation Technique ◽  
Lattice Images ◽  
Dislocation Core Structure ◽  
Type Lattice ◽  
Direct Inspection

Dislocations in silicon produced by plastic deformation are generally dissociated into partials. 60° dislocations (Burgers vector type 1/2[101]) are dissociated into 30°(Burgers vector type 1/6[211]) and 90°(Burgers vector type 1/6[112]) dislocations. The 30° partials may be either of “glide” or “shuffle” type. Lattice images of the 30° dislocation have been obtained with a JEM 100B, and with a JEM 200Cx. In the aforementioned experiments a reasonable but imperfect match was obtained with calculated images for the “glide” model. In the present experiment direct structure images of 30° dislocation cores have been obtained with a JEOL 4000EX. It is possible to deduce the 30° dislocation core structure by direct inspection of the images. Dislocations were produced by compression of single crystal Si (sample preparation technique described in Alexander et al.).

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