The interaction between the gelatin-binding domain of fibronectin and the attachment ofPasteuria penetransendospores to nematode cuticle

Parasitology ◽  
2001 ◽  
Vol 123 (3) ◽  
pp. 271-276 ◽  
Author(s):  
S. MOHAN ◽  
S. FOULD ◽  
K. G. DAVIES

Pasteuria penetransis a Gram-positive endospore-producing bacterium that is a parasite of root-knot nematodes. Attachment of endospores to the cuticle of the nematode is the first stage in the infection process. Western blot analysis with monoclonal and polyclonal antibodies that recognize the 30 kDa heparin-binding domain (HBD) and the 45 kDa gelatin-binding domain (GBD) fragments of human fibronectin (Fn) revealed a series of polypeptides of approximately 40, 45 and 55 kDa present in crude cuticle extracts ofMeloidogyne javanica2nd-stage juveniles. The results suggest that the structure of the nematode fibronectin is different to the fibronectins so far characterized. Pre-treatment of endospores ofPasteuriawith either the HBD or the GBD was found to inhibit binding to the nematode cuticle. The larger GBD fragment was the most effective at blocking adhesion. Pre-treatment of the GBD fragment with gelatin prevented the GBD fragment from inhibiting endospore attachment to the nematode cuticle.

2002 ◽  
Vol 70 (3) ◽  
pp. 1287-1292 ◽  
Author(s):  
Rajamouli Pasula ◽  
Paul Wisniowski ◽  
William J. Martin

ABSTRACT Mycobacterium tuberculosis remains a major cause of pulmonary infection worldwide. Attachment of M. tuberculosis organisms to alveolar macrophages (AMs) represents the earliest phase of primary infection in pulmonary tuberculosis. In this study fibronectin (Fn), an adhesive protein, is shown to bind M. tuberculosis organisms and facilitates attachment of M. tuberculosis to murine AMs. A monoclonal antibody (MAb) specific to the heparin binding domain (HBD) of Fn decreases 125I-Fn binding to M. tuberculosis; whereas MAbs specific to either the cell binding domain (CBD) or the gelatin binding domain (GBD) have no effect on Fn binding to M. tuberculosis. In the presence of exogenous Fn (10 μg/ml) M. tuberculosis attachment to AMs increased significantly from control levels (means ± standard errors of the means) of 11.5% ± 1.1% to 44.2% ± 4.2% (P < 0.05). Fn-enhanced attachment was significantly decreased from 44.2% ± 4.2% to 10.8% ± 1.2% (P < 0.05) in the presence of anti-Fn polyclonal antibodies. The attachment is also inhibited in the presence of MAbs specific for the HBD and CBD, whereas MAbs specific to GBD did not affect the attachment. Further, an Fn cell binding peptide, Arg-Gly-Asp-Ser (RGDS), decreased the attachment from 44.2% ± 4.2% to 15.3% ± 1.2% (P < 0.05), whereas addition of a control peptide, Arg-Gly-Glu-Ser (RGES) did not affect the attachment (40.5% ± 1.8%). These results suggest that Fn-mediated attachment of M. tuberculosis can occur through the binding of Fn to the AM via the CBD and to M. tuberculosis organisms via the HBD.


Author(s):  
Silvia Bozzini ◽  
Valeria Falcone ◽  
Pier Giulio Conaldi ◽  
Livia Visai ◽  
Luigi Biancone ◽  
...  

Parasitology ◽  
1989 ◽  
Vol 98 (1) ◽  
pp. 155-164 ◽  
Author(s):  
A. F. Bird ◽  
Ingrid Bonig ◽  
A. Bacic

SummaryThe influence of various agents on the adhesion of endospores of Pasteuria penetrans to the nematode Meloidogyne javanica was studied. Similarly, but to a lesser degree, we have also studied the adhesion of conidia of the fungus Dilophospora alopecuri and the coryneform bacterium Clavibacter sp. (syn. Corynebacterium rathayi) to the nematode Anguina agrostis (syn. A. funesta). Reduction in the degree of both spore and conidial attachment following their pre-treatment with periodate and the presence of PAS staining material on spores, conidia and bacteria implicated carbohydrate in these interactions. Tests involving both unbound and FITC-bound lectins demonstrated that wheat germ agglutinin (WGA) can inhibit the degree of attachment of P. penetrans to M. javanica and that this inhibition can be overcome by pre-treatment of the lectin with N, N′-diacetyl chitobiose. Endospores of P. penetrans, amphid and buccal secretions of 2nd-stage larvae of M. javanica and the cuticle and excretory pore secretions of 2nd-stage dauer larvae of A. agrostis bound WGA, indicating that accessible N-acetyl-D-glucosamine residues are present on these structures. Endospores of P. penetrans also bound Con A, indicating the presence of accessible α-D-glucose/α-D-mannose residues on their surface.


2000 ◽  
Vol 24 (1) ◽  
pp. 43-51 ◽  
Author(s):  
H Song ◽  
J Beattie ◽  
IW Campbell ◽  
GJ Allan

Using site-directed mutagenesis, we have undertaken a study of a potential IGF-binding site in the C-terminal domain of rat IGFBP-5, lying close to or within a previously described heparin-binding domain (residues 201-218) in this protein. After analysis of binding activity using three different methods - ligand blotting, solution phase equilibrium binding and biosensor measurement of real-time on- and off-rates - we report that the mutation of two highly conserved residues within this region (glycine 203 and glutamine 209) reduces the affinity of the binding protein for both IGF-I and IGF-II, while having no effect on heparin binding. In addition, we confirm that mutation of basic residues within the heparin-binding domain (R201L, K202E, K206Q and R214A) results in a protein that has attenuated heparin binding but shows only a small reduction in affinity for IGF-I and -II. Previous findings have described the reduction in affinity of IGFBP-5 for IGFs that occurs after complexation of the binding protein with heparin or other components of the extracellular matrix (ECM) and have postulated that such an interaction may result in conformational changes in protein structure, affecting subsequent IGF interaction. Our data suggesting potential overlap of heparin- and IGF-binding domains argue for a more direct effect of ECM modulation of the affinity of IGFBP-5 for ligand by partial occlusion of the IGF-binding site after interaction with ECM.


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