Click chemistry-based tracking reveals putative cell wall-located auxin binding sites in expanding cells

Paromomycin (Humatin, Parke Davis & Co.), a broad-spectrum aminoglycosidic antibiotic, inhibits the incorporation of amino acids into the trypsinsoluble protein fraction of Staphylococcus aureus 257. Protein synthesis is inhibited immediately, but the synthesis of cell-wall mucopeptide and alcohol-soluble proteins and lipids is not affected for approximately 35 min after antibiotic addition to actively growing cells. Paromomycin, at the ribosomal level, prevents the attachment of amino acyl-s-RNA and causes accumulation of m-RNA.Divalent cations (Ca++ and Mg++) antagonize the bactericidal action of paromomycin and interfere with the in vivo binding of the antibiotic on both the cell surface and the intracellular binding sites. In vitro binding to free ribosomes can be prevented and reversed by both monovalent and divalent cations.Using a "cylinder-plate" method, involving the displacement of antibiotic from cellular fractions by 0.2 M MgCl2, the antibiotic can be recovered from the ribosomes, cytoplasm, and the cell wall of paromomycin-sensitive S. aureus cells, but is not found in any of these fractions isolated from paromomycin-resistant cells developed from the sensitive parent strain. The resistant mutants apparently have lost the ability to adsorb and transport the antibiotic into the cell.

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Interaction of the Crystalline Bacterial Cell Surface Layer Protein SbsB and the Secondary Cell Wall Polymer of Geobacillus stearothermophilus PV72 Assessed by Real-Time Surface Plasmon Resonance Biosensor Technology

Journal of Bacteriology ◽

10.1128/jb.186.6.1758-1768.2004 ◽

2004 ◽

Vol 186 (6) ◽

pp. 1758-1768 ◽

Cited By ~ 63

Author(s):

Christoph Mader ◽

Carina Huber ◽

Dieter Moll ◽

Uwe B. Sleytr ◽

Margit Sára

Keyword(s):

Cell Wall ◽

Surface Plasmon Resonance ◽

Real Time ◽

Surface Plasmon ◽

Plasmon Resonance ◽

Binding Sites ◽

Secondary Cell Wall ◽

Sensor Chip ◽

Geobacillus Stearothermophilus ◽

Secondary Cell Wall Polymer

ABSTRACT The interaction between S-layer protein SbsB and the secondary cell wall polymer (SCWP) of Geobacillus stearothermophilus PV72/p2 was investigated by real-time surface plasmon resonance biosensor technology. The SCWP is an acidic polysaccharide that contains N-acetylglucosamine, N-acetylmannosamine, and pyruvic acid. For interaction studies, recombinant SbsB (rSbsB) and two truncated forms consisting of either the S-layer-like homology (SLH) domain (3SLH) or the residual part of SbsB were used. Independent of the setup, the data showed that the SLH domain was exclusively responsible for SCWP binding. The interaction was found to be highly specific, since neither the peptidoglycan nor SCWPs from other organisms nor other polysaccharides were recognized. Data analysis from that setup in which 3SLH was immobilized on a sensor chip and SCWP represented the soluble analyte was done in accordance with a model that describes binding of a bivalent analyte to a fixed ligand in terms of an overall affinity for all binding sites. The measured data revealed the presence of at least two binding sites on a single SCWP molecule with a distance of about 14 nm and an overall K d of 7.7 × 10−7 M. Analysis of data from the inverted setup in which the SCWP was immobilized on a sensor chip was done in accordance with an extension of the heterogeneous-ligand model, which indicated the existence of three binding sites with low (K d = 2.6 × 10−5 M), medium (K d = 6.1 × 10−8 M), and high (K d = 6.7 × 10−11 M) affinities. Since in this setup 3SLH was the soluble analyte and the presence of small amounts of oligomers in even monomeric protein solutions cannot be excluded, the high-affinity binding site may result from avidity effects caused by binding of at least dimeric 3SLH. Solution competition assays performed with both setups confirmed the specificity of the protein-carbohydrate interaction investigated.

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Synthesis of calix[4]crowns containing soft and hard ion binding sites via click chemistry

New Journal of Chemistry ◽

10.1039/b816467c ◽

2009 ◽

Vol 33 (4) ◽

pp. 725-728 ◽

Cited By ~ 28

Author(s):

Junyan Zhan ◽

Demei Tian ◽

Haibing Li

Keyword(s):

Click Chemistry ◽

Binding Sites ◽

Ion Binding ◽

Ion Binding Sites

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Separation and localization of two classes of auxin binding sites in corn coleoptile membranes

Planta ◽

10.1007/bf00390839 ◽

1976 ◽

Vol 130 (1) ◽

pp. 15-21 ◽

Cited By ~ 72

Author(s):

Susan Batt ◽

Michael A. Venis

Keyword(s):

Binding Sites ◽

Auxin Binding

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Postharvest Infiltration of Polyamines and Calcium Influences Ethylene Production and Texture Changes in `Golden Delicious' Apples

Journal of the American Society for Horticultural Science ◽

10.21273/jashs.118.6.801 ◽

1993 ◽

Vol 118 (6) ◽

pp. 801-806 ◽

Cited By ~ 45

Author(s):

Chien Yi Wang ◽

William S. Conway ◽

Judith A. Abbott ◽

George F. Kramer ◽

Carl E. Sams

Keyword(s):

Cell Wall ◽

Fruit Quality ◽

Malus Domestica ◽

Ethylene Production ◽

Binding Sites ◽

Golden Delicious

Prestorage infiltration of `Golden Delicious' apples (Malus domestica Borkh.) with calcium (Ca) retarded texture changes during storage at 0C and inhibited ethylene production of the fruit at 20C. Infiltration of the fruit with the polyamines (PA) putrescine (PUT) or spermidine (SPD) also altered texture changes, but did not inhibit ethylene production. When the fruit were treated with Ca first and then with PA, cell wall-hound Ca concentrations increased 4-fold, but PA levels in the cell wall increased only slightly. When the fruit were treated with PA first and then with Ca, PA levels in the cell wall increased 3-fold, but Ca concentration increased only 2-fold. These results indicate that Ca and PA may he competing for the same binding sites in the cell wall and that the improvement of fruit quality during storage by these cations could involve strengthening of the cell wall.

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