| HOME | HELP | FEEDBACK | SUBSCRIPTIONS | ARCHIVE | SEARCH | TABLE OF CONTENTS |
|
|
|
|||||||
|
|||||||||
1 University of Pavia, Department of Biochemistry, Viale Taramelli 3/B, 27100 Pavia, Italy
2 Department of Veterinary Science and Microbiology, The University of Arizona, Tucson, AZ 85721, USA
Correspondence
P. Speziale
pspeziale{at}unipv.it
 |
ABSTRACT |
|---|
 TOP ABSTRACT INTRODUCTIONMETHODSRESULTSDISCUSSIONREFERENCES |
|---|
-helical component and that both the proteins have a well-defined tertiary structure.
|
INTRODUCTION |
|---|
|
TOPABSTRACTINTRODUCTIONMETHODSRESULTSDISCUSSIONREFERENCES |
|---|
). As an opportunistic pathogen, A. pyogenes can cause a variety of suppurative diseases in animals compromised by previous microbial infection or trauma. Economically significant disease includes liver abscessation in beef cattle, and pneumonia and arthritis in swine (Jost & Billington, 2005). A. pyogenes is armed with several factors that contribute to its pathogenesis, including a cholesterol-dependent cytolysin, pyolysin (Billington et al., 1997), several proteases (Schaufuss et al., 1989) and a number of adhesive mechanisms, including two cell-surface neuraminidases (Jost et al., 2002) and a collagen-binding protein, CbpA (Esmay et al., 2003).
Adhesion to the host is an important first step in bacterial colonization and disease pathogenesis. Bacteria target a wide variety of host molecules, but a common mechanism used by a number of pathogens is binding to components of the host extracellular matrix (ECM). In Gram-positive organisms, ECM binding is almost exclusively the property of a number of bacterial surface proteins designated microbial surface components recognizing adhesive matrix molecules (MSCRAMMs) (Foster & Höök, 1998). CbpA is a 121.9 kDa, surface-expressed protein that binds type I collagen, and is involved in mediating adherence to epithelial and fibroblast cell lines (Esmay et al., 2003). As reported for other MSCRAMMs (Foster & Höök, 1998), CbpA has a modular domain structure consisting of an N-terminal signal peptide, a non-repetitive A region, and four repeated units (B region), followed by a cell-wall anchor region, a transmembrane segment, and a short positively charged cytoplasmic tail. In addition, this protein has amino acid similarity to the collagen-binding adhesin CNA of Staphylococcus aureus.
A number of studies have directly linked collagen-binding MSCRAMMs to disease processes in collagen-rich tissues. Staph. aureus CNA has been demonstrated as a virulence factor in several experimental animal models, including colonization of the joints in mice (Xu et al., 2004a). Similarly, ACE, the collagen adhesin of Enterococcus faecalis, is important for adherence to dentin in tooth root canals (Hubble et al., 2003). The crtical role of the bacterial attachment to collagen is further indicated by identification of collagen-binding proteins in a variety of micro-organisms such as M3 protein from Streptococcus pyogenes (Dinkla et al., 2003), protein FOG in Streptococcus dysgalactiae equisimilis (Nitsche et al., 2006), YadA of enteropathogenic Yersinia species (Nummelin et al., 2004) and CbsA from Lactobacillus crispatus (Antikainen et al., 2002).
CbpA is present in 48 % of A. pyogenes isolates; however, 100 % of turkey osteomyelitis isolates were cbpA+ (Esmay et al., 2003), possibly implicating CbpA in the pathogenesis of osteomyelitis.
This study further extends the biochemical analysis of A. pyogenes CbpA with respect to its binding properties for collagens, as well as to structure and immunological correlations with other bacterial collagen-binding proteins.
|
METHODS |
|---|
|
TOPABSTRACTINTRODUCTIONMETHODSRESULTSDISCUSSIONREFERENCES |
|---|
). Recombinant Acm was a generous gift from Dr B. E. Murray (University of Texas Medical School, Houston, TX, USA). CNA19 (residues 151–319), and ACE40 (residues 32–367) were kindly provided by Dr M. Höök (Texas A&M University Health Science Center, Houston, TX, USA).
Collagens and CB peptides.
Type I collagen from calf skin was a gift from Dr R. Tenni (Dept of Biochemistry, University of Pavia, Italy). CB peptides were obtained by cleavage of type I collagen with CNBr and purified by gel-filtration chromatography followed by ion-exchange chromatography (Rossi et al., 1996). Type II, IX and XI collagens were purified from bovine nasal septum (Reese & Mayne, 1981). Type II collagen CNBr peptides were isolated essentially following the procedures used for peptides from type I collagen (Rossi et al., 1996). All collagens and peptides were analysed for purity by a quantitative Hyp assay (Huszar et al., 1980), by electrophoresis in denaturing conditions (Laemmli, 1970), and by N-terminal sequencing for some peptides, and for conformation by means of circular dichroism spectroscopy.
Expression and purification of CbpA proteins.
Cloning of recombinant CbpA, lacking the signal peptide (residues 28–1151), and the A domain of CbpA (residues 29–355) was performed as reported previously (Esmay et al., 2003).
The fusion proteins, containing an N-terminal His-tag, were purified by immobilized metal chelate affinity chromatography and gel filtration chromatography on a Superose 12 HR column fitted on an FPLC system. The purity of the isolated proteins was assessed by SDS-PAGE.
Bacteria and growth conditions.
Escherichia coli DH5MCR harbouring plasmid pJGS591 (Esmay et al., 2003) was routinely grown in Luria broth or in Luria agar (Difco) containing 100 µg ampicillin ml–1 at 37 °C. Enterococcus faecium 395 cultures were grown in Brain Heart Infusion (BHI; Difco) at 37 °C. Enterococcus faecalis 706897 was grown in BHI medium at 46 °C. A. pyogenes BBR1 was grown in BHI supplemented with 5 % (w/v) newborn calf serum and 5 µg tetracycline ml–1 at 37 °C.
Biotin labelling of CbpA.
CbpA (0.5 mg) dissolved in 0.5 ml PBS, pH 7.4, was mixed with 0.5 ml 0.2 M sodium borate buffer, pH 8.0, and 7.5 mg N-hydroxysuccinimidobiotin (NHS-biotin) (Sigma) dissolved in 0.1 ml DMSO, and incubated at 22 °C overnight with end-over-end mixing. The labelling mixture was dialysed against PBS and stored at –20 °C in small aliquots.
Polyclonal and monoclonal antibodies.
Antibodies to recombinant CbpA, ACE40, CNA19 and Acm were raised in BALB/c mice. Injections were given intraperitoneally four times at 1 week intervals with 50 µg of the antigen emulsified with an equal volume of complete Freund's adjuvant for the first immunization, followed by three injections in Freund's incomplete adjuvant. The mice were bled and the sera were tested for reactivity against the corresponding antigen.
The mAbs against ACE40 and CNA19 were produced essentially as described by Köhler & Milstein (1975) with minor modifications. Hybridoma supernatants were screened for reactivity with the appropriate antigen immobilized on microtitre plates and positive clones were further characterized by ELISA and Western blotting.
Antibodies from the sera and hybridoma supernatants were purified by affinity chromatography on protein G-Sepharose according to the recommendations of the manufacturer (Amersham Biosciences). Isotyping of the mAbs produced was performed using a Mouse-Typer subisotyping kit (Bio-Rad). All the mAbs were found to belong to the IgG isotype.
ELISA.
The binding of CbpA proteins to plasma or ECM proteins was determined in an ELISA-type assay. Unless otherwise stated, microtitre wells were coated with 100 µl of 10 µg ml–1 of the indicated proteins dissolved in 50 mM sodium carbonate, pH 9.5. To block additional protein-binding sites, the wells were treated for 1 h with 200 µl 2 % (w/v) BSA in PBS at 22 °C. The wells were then washed with PBST (PBS+0.5 %, v/v, Tween 20) and incubated for 1 h with 1 µg CbpA or region A of CbpA. After washing, bound ligand was incubated for 1 h with 1 µg mouse anti-CbpA IgG followed by 1 h incubation with peroxidase-conjugated rabbit anti-mouse IgG (Dako). The conjugated enzyme was allowed to react with o-phenylendiamine dihydrochloride (Sigma) and absorbance at 490 nm was measured using a microplate reader (Bio-Rad). To calculate the relative association constant (Ka) values of CbpA proteins for type I and II collagens and collagen peptides from the saturation kinetics, the following equation was used: A=Amax[CbpA]Ka/(1+Ka[CbpA]).
The reported KD values were calculated as the reciprocal of the corresponding association constants.
To measure the adsorption of each protein to the plates, protein bound to the wells was determined by using a BCA protein assay kit, Microplate Procedure, Protocol #2161297A (Pierce): in these conditions, a 80–90 % coating efficiency was detected for each protein tested.
The binding of CbpA to collagen in the presence of anti-CbpA antibodies was studied by incubating collagen-coated microtitre plates (1 µg per well) with 1 µg biotin-labelled CpbA for 1 h at 22 °C. CbpA bound to collagen was detected by the addition of a 1 : 2000 dilution of avidin-peroxidase followed by a chromogenic substrate, and absorbance at 490 nm was measured using a microplate reader.
Attachment of A. pyogenes cells to collagen-coated wells was performed by incubating microtitre plates coated with collagen type I (1 µg per well) with 5x107 bacterial cells for 90 min. After three washes, collagen-bound bacteria were incubated with 1 µg of a rabbit anti-A. pyogenes IgG. Binding of antibody to bacteria was detected by addition of a peroxidase-labelled goat anti-rabbit secondary antibody.
Immunological reactivity of collagen-binding proteins.
Cross-reactivity of recombinant adhesins from A. pyogenes (CbpA), Staph. aureus (CNA), Ent. faecalis (ACE) and Ent. faecium (Acm) was analysed by incubating adhesin-coated microtitre wells (1 µg per well) with 1 µg mouse IgG isolated from immune sera against each adhesin or with 1 µg of individual mouse monoclonal antibodies raised against ACE40. Binding of the antibodies to the wells was detected by addition of 1 µg peroxidase-conjugated rabbit anti-mouse antibody.
Immunological reactivity of bacterial species expressing collagen-binding proteins.
Microtitre wells were coated with 100 µl of bacterial cells (5x107 per well) in PBS, overnight at 37 °C. After incubating with 2 % (w/v) BSA the bacteria-coated wells were washed with PBST and incubated for 90 min with 1 µg IgG of individual monoclonal antibodies against CNA19 or ACE40. The wells were washed three times and incubated with 1 : 1000 dilution of peroxidase-conjugated rabbit anti-mouse antibody. The conjugated enzyme was allowed to react with o-phenylendiamine dihydrochloride and absorbance at 490 nm was measured using a microplate reader.
Circular dichroism (CD) spectroscopy.
Far-UV (195–250 nm) and near-UV (250–320 nm) CD measurements were performed at 20 °C in 0.1 and 1.0 cm pathlength quartz cuvettes, respectively. CD spectra were recorded on a Jasco J-720 spectropolarimeter. The results are expressed as the mean residue ellipticity assuming a mean residue weight of 110 amino acid residues. All the spectroscopic measurements were performed in 20 mM phosphate buffer pH 7.4. Six scans were averaged for each spectrum, and the contribution from the buffer was subtracted in each case. Quantification of secondary structural components was performed using the deconvolution programs CONTIN, CDSSTR and SELCON3.
Intrinsic tryptophan fluorescence.
The intrinsic tryptophan fluorescence of 0.2 µM CbpA proteins in PBS was examined with a Jasco FP-6500 spectrofluorimeter at 22 °C. The excitation wavelength was set at 295 nm (5 nm slit width) while monitoring emission from 305 to 400 nm (5 nm slit width). Quenching of tryptophan fluorescence after the addition of collagen (from 0.0015 to 0.1 µM) was analysed via a modified Stern–Volmer plot (Eftink & Ghiron, 1981) as follows. The F0/(F0–F) ratio (where F0 and F are the fluorescence intensities at 338 nm in the absence and presence of collagen, respectively) plotted against the reciprocal of CbpA concentration yields a straight line, the intercept of which on the x axis equals the value of the association constant (Ka) for collagen.
|
RESULTS |
|---|
|
TOPABSTRACTINTRODUCTIONMETHODSRESULTSDISCUSSIONREFERENCES |
|---|
). To analyse the specificity of interactions of CbpA with collagen, we immobilized a number of ECM or plasma proteins onto microtitre wells and then incubated the plates with recombinant full-length CbpA or region A of CbpA. Binding of recombinant CbpAs to immobilized proteins was detected by addition of an anti-CbpA antibody to the wells. In confirmation of previous data, CbpA proteins bound to type I collagen but not to other ligands such as laminin, elastin, ovalbumin or albumin (Fig. 1a). Interestingly, CbpA and its A domain were found to interact also with fibronectin and to a lesser extent with fibrinogen. The ability of CbpA to bind both collagen and fibronectin appeared to be a peculiar property of CbpA, because other bacterial collagen-binding proteins such as CNA from Staph. aureus and ACE from Ent. faecalis did not bind to fibronectin (data not shown). With exclusion of collagen V and IX, for which CbpA showed reduced binding, the binding of CbpA to genetically distinct collagen types was very similar (Fig. 1b).
|
).
Saturable binding of CbpA to collagens and CB peptides
To provide further evidence that CbpA was a relevant partner for binding to collagen, microtitre wells coated with type I collagen were incubated with increasing amounts of CbpA or region A of CbpA. As shown in Fig. 2, full-length CbpA and region A bound to collagens in a dose-dependent fashion, whereas the binding to the wells coated with albumin was minimal (data not shown). From these assays we estimated the KD value of full-length CbpA and region A for type I collagen as 5.26 and 1.12 nM, respectively (Table 1). KD values in the same range were obtained by incubating increasing concentrations of CbpA or region A of CbpA with surface-coated type II collagen (Table 1).
|
|
Preliminary analysis indicated that the binding of type I or II collagen to CbpA resulted in quenching of intrinsic tryptophan fluorescence (ITF). We therefore measured the fluorescence of CbpA in the presence of increasing concentrations of collagen I or II when the protein was excited at 295 nm (Fig. 3a, b). Collagens quenched the intrinsic fluorescence of CbpA in a dose-dependent manner, whereas no quenching of fluorescence emission was detected when only PBS or non-collagenous proteins were added to the mixtures of the recombinant proteins. Analysis of the tryptophan quenching data by a modified Stern–Volmer plot gave KD values of 2.23 and 1.0 nM, respectively, for collagens I and II (Fig. 3a, b, Table 1). Affinities of region A for type I and II collagens as measured by ITF were 2.27 and 6.86 nM, respectively (Table 1).
|
) although a preferential binding of CbpA to the peptides CB3.8(I), CB7(I), CB8(I) and CB11(II) was observed. However, it remains to be determined whether the better recognition of these peptides by CbpA reflects the interaction with specific binding sites or is the result of a differential coating efficiency when peptides of different size are tested.
|
).
Anti-CbpA antibodies block interaction of CbpA with collagen
Purified IgG antibodies isolated from an antiserum raised against full-length CbpA were tested for their ability to inhibit CbpA-dependent A. pyogenes adherence to a collagen substrate. Anti-CbpA IgG was a potent inhibitor of cell adhesion, causing 85 % inhibition at 10 µg ml–1 (Fig. 5). A similar blocking effect was obtained when collagen-coated wells were incubated with biotin-labelled CbpA in the presence of increasing concentrations of the same antibody (data not shown). Conversely, no effect was detected when either bacteria or the recombinant CbpA were incubated with immobilized collagen in the presence of IgG isolated from a pre-immune serum.
|
). Thus, it was of interest to analyse the possible immunological cross-reactivity of these adhesins. To this end, CbpA was investigated in ELISA format for the reactivity with mAbs against the N2 module of region A of CNA (CNA19) (Visai et al., 2000) or ACE40, which are recombinant segments encompassing the collagen-binding site in these two adhesins (Patti et al., 1993; Rich et al., 1999). mAbs against CNA strongly reacted with the immobilized CNA19 fragment, but did not recognize immobilized CbpA to any degree (data not shown). The collection of mAbs raised against ACE40 reacted well with homologous antigen, and a number of mAbs (3E11, 8A1, 9D4, 10E4, 11A6, 11C7, 11D12 and 12A2) also recognized CbpA (Fig. 6a). However, the relative affinity of these antibodies for CbpA epitopes was reduced 
100-fold compared to that for ACE homologous epitopes (KD values of 100 nM vs 1 nM, respectively). To analyse whether similar cross-reactivity would be observed under more physiological conditions, the panels of mAbs against CNA and ACE were examined for reactivity with adhesins directly expressed on the surface of bacteria. Consistent with the poor cross-reactivity of the anti-CNA monoclonal antibodies with recombinant CbpA, the mAbs against CNA did not show any reactivity towards CbpA expressed on the surface of A. pyogenes (data not shown). Conversely, an even wider reactivity was noticed following incubation of the panel of anti-ACE mAbs with immobilized cells of A. pyogenes, indicating a more favourable display of the epitopes when CbpA was presented on the bacterial cell surface (Fig. 6b). Similar results were obtained when CbpA or A. pyogenes cells were reacted with polyclonal antibodies against CNA or ACE40. A lack of cross-reactivity was observed when recombinant CbpA or A. pyogenes cells were incubated with polyclonal antibodies against Acm (data not shown).
|
The spectral properties of full-length CbpA and of region A were investigated by CD. Far-UV CD spectra of the full-length CbpA and the A domain showed a single maximum and minimum at 200 and 215–220 nm, respectively (Fig. 7a). Deconvolution of the CD spectra by using three independent procedures showed that the proteins are mainly composed of β-sheets and indicated the relative content of secondary structure elements of both the proteins (Table 2). The near-UV CD spectra of CbpA and of region A indicated that both proteins are folded into a compact tertiary structure (Fig. 7b) and the differences in dichroic activity for region A may be due to the lower number of aromatic residues. All the aromatic residues contribute to the near-UV CD spectra of CbpA and region A: signals around the region 260–270 nm are attributable to phenyalanine residues, signals from 275 to 288 nm are attributable to tyrosine and those from 290 to 300 nm to tryptophan. The near-UV CD spectrum of CbpA exhibited maxima at 278, 285, 290 and 294 nm. The near-UV CD spectrum of region A showed a positive band in the tryptophan region but differed at shorter wavelengths from those of full-length CbpA. In conclusion, the spectral profiles of both the proteins suggested that they have a well-defined tertiary structure and that all the aromatic residues are locked into tertiary contacts.
|
|
|
DISCUSSION |
|---|
|
TOPABSTRACTINTRODUCTIONMETHODSRESULTSDISCUSSIONREFERENCES |
|---|
), ACE from Ent. faecalis (Nallapareddy et al., 2000) and Acm from Ent. faecium (Nallapareddy et al., 2003). We previously identified the first A. pyogenes MSCRAMM, CbpA, which is capable of binding type I collagen (Esmay et al., 2003). In this study we further examined the binding properties of CbpA to collagens, compared the immunological cross-reactivity of CbpA with other bacterial collagen-binding adhesins and analysed some of the structural aspects of the protein. First, we demonstrated that CbpA and the A region of CbpA bind to type I and II collagen specifically, saturably and with similar affinities. The apparent KD values of the interaction between type I or II collagen and CbpA proteins are in the range of 1–15 nM, as determined by ELISA and ITF; these values are lower than those observed for the collagen-binding proteins rBA0871A and rBA5258A from Bacillus anthracis (Xu et al., 2004b) and ACE from Ent. faecalis (Rich et al., 1999).
An interesting question is whether CbpA behaves promiscuously in its binding to different collagen types. Our data indicate that this is the case. In fact, CbpA recognizes almost all the collagen types tested. This feature could broaden the spectrum of potential A. pyogenes infection sites and make this bacterium less dependent on local variation in tissue composition and availability of specific components, which is consistent with the ability of this organism to infect a variety of host species and tissue types (Jost & Billington, 2005). In addition, CbpA binds a number of peptides generated by CNBr cleavage of type I and II collagens.
The binding of CbpA to different CB peptides is consistent with the presence of highly repetitive sequences in the collagen -chains. This suggests that the CbpA binding sites are scattered over the collagen molecule and that CbpA can bind many sites along the collagen molecule. In addition, on the basis of the tendency of CB peptides to form homologous homotrimers (Rossi et al., 1996) and the similar affinity of CbpA for both collagens and CB peptides we can speculate that collagen triple helix is the recognition element for CbpA binding. Recently, several bacterial surface proteins that were regarded as binding a single ligand were shown to bind additional host proteins. For example, the fibronectin-binding proteins FnbpA and FnbpB from Staph. aureus also recognize fibrinogen and elastin (Roche et al., 2004), while ClfB, originally described as a fibrinogen-binding staphylococcal receptor, binds to cytokeratin 10 (Walsh et al., 2004). In line with this, here we show a second binding activity for CbpA. Both recombinant full-length CbpA and the A region of CbpA bind fibronectin. In addition, we tested the competitive effect of type I collagen on CbpA binding to surface-coated fibronectin or, conversely, the potential interference of soluble fibronectin on the binding of CbpA to immobilized type I collagen in ELISA assays. In these conditions collagen did not affect CbpA binding to fibronectin, nor did fibronectin influence CbpA binding to collagen (data not shown and Fig. 1c). These findings rule out the possibility that binding of CbpA to either ligand could be attributed to an artefact of collagen or fibronectin contamination. Moreover, the absence of cross-inhibition by one ligand on the binding of the other one to CbpA clearly indicates that collagen and fibronectin recognize different subsites of CbpA
Vaccination of animals with a recombinant form of CNA or RspA, the collagen adhesins of Staph. aureus and Erysipelothrix rhusiopathiae, was shown to protect against challenge by wild-type Staph. aureus (Nilsson et al., 1998) and E. rhusiopathiae (Shimoji et al., 2003), respectively. The finding that CbpA is a good immunogen and that antibodies against CbpA inhibit A. pyogenes attachment to immobilized collagen suggests that CbpA might be a vaccine candidate for combating infections by this bacterium.
It has been shown that region A of CbpA exhibits similarity with A regions of other collagen-binding proteins, with the most similarity to the A region of CNA (percentage sequence identity and similarity 28 % and 68 %, respectively). Surprisingly, we found that the immunological cross-reactivity between CbpA and CNA is very limited, as suggested by the weak recognition by the panel of mAbs against CNA of either isolated, recombinant or A. pyogenes surface-exposed CbpA. In contrast, in spite of the relatively lower sequence similarity betweeen the A domains of CbpA and ACE (24 % identity, 54 % similarity), a number of anti-ACE monoclonal antibodies recognize CbpA in an ELISA. However, the affinity of these anti-ACE mAbs is 100-fold lower than that for the homologous epitopes. An even wider response is observed by incubating A. pyogenes cells with anti-ACE mAbs, indicating that some epitopes that are exposed on the bacterial surface are more accessible than the corresponding ones present in the recombinant protein immobilized onto microtitre wells.
It has been shown that a recombinant form of A region of CNA (Zong et al., 2005) or ACE (Rich et al., 1999) has a β-sheet structure that folds into an Ig-like fold. Our CD analysis indicates that CbpA and the A region of CbpA are composed primarily of β-sheet structures. For this reason and on the basis of the analysis of the three-dimensional structure of A region by homology modelling (data not shown), it is plausible that the CbpA folds similarly to ACE and CNA and adopts an Ig-like fold. In addition, the finding that full-length CbpA and its A region have a substantially similar percentage of β-sheet structure suggests that, consistent with the structure of the repetitive units of CNA (Deivanayagam et al., 2000), the B domains of CbpA might have a β-sheet arrangement.
Earlier studies indicated that the B domains of CNA neither bind collagen nor influence the A region's collagen-binding activity (Rich et al., 1998). These B region repeat units have been proposed to serve as a stalk that projects the A region away from the staphylococcal cell surface and positions it for binding to collagen. Thus, it is reasonable to suppose that the B domain in CbpA has a similar function. In conclusion, as previously reported for CNA and ACE, CbpA is composed primarily of β-sheet structures, with a minor -helical component, but the global arrangement of such secondary structural elements in this MSCRAMM remains to be determined.
|
ACKNOWLEDGEMENTS |
|---|
Edited by: P. W. O'Toole
|
REFERENCES |
|---|
|
TOPABSTRACTINTRODUCTIONMETHODSRESULTSDISCUSSIONREFERENCES |
|---|
Billington, S. J., Jost, B. H., Cuevas, W. A., Bright, K. R. & Songer, J. G. (1997). The Arcanobacterium (Actinomyces) pyogenes hemolysin, pyolysin, is a novel member of the thiol-activated cytolysin family. J Bacteriol 179, 6100–6106.
Deivanayagam, C. C., Rich, R. R., Carson, M., Owens, R. T., Danthuluri, S., Bice, T., Höök, M. & Narayana, S. V. (2000). Novel fold and assembly of the repetitive B region of the Staphylococcus aureus collagen-binding surface protein. Structure 8, 67–78.[Medline]
Dinkla, K., Rohde, M., Jansen, W. T., Kaplan, E. L., Chhatwal, G. S. & Talay, S. R. (2003). Rheumatic-fever associated Streptococcus pyogenes isolates aggregate collagen. J Clin Invest 111, 1905–1912.[CrossRef][Medline]
Eftink, M. R. & Ghiron, C. A. (1981). Fluorescence quenching studies with proteins. Anal Biochem 114, 199–227.[CrossRef][Medline]
Esmay, P. A., Billington, S. J., Link, M. A., Songer, J. G. & Jost, B. H. (2003). The Arcanobacterium pyogenes collagen binding protein, CbpA, promotes adhesion to host cells. Infect Immun 71, 4368–4374.
Foster, T. J. & Höök, M. (1998). Surface protein adhesins of Staphylococcus aureus. Trends Microbiol 6, 484–488.[CrossRef][Medline]
Hubble, T. S., Hatton, J. F., Nallapareddy, S. R., Murray, B. E. & Gillespie, M. J. (2003). Influence of Enterococcus faecalis proteases and the collagen-binding protein, Ace, on adhesion to dentin. Oral Microbiol Immunol 18, 121–126.[CrossRef][Medline]
Huszar, G., Maiocco, J. & Naftolin, F. (1980). Monitoring of collagen and collagen fragments in chromatography of protein mixtures. Anal Biochem 105, 424–429.[CrossRef][Medline]
Jost, B. H. & Billington, S. J. (2005). Arcanobacterium pyogenes: molecular pathogenesis of an animal opportunist. Antonie Van Leeuwenhoek 88, 87–102.[CrossRef][Medline]
Jost, B. H., Songer, J. G. & Billington, S. J. (2002). Identification of a second Arcanobacterium pyogenes neuraminidase and involvement of neuraminidase activity in host cell adhesion. Infect Immun 70, 1106–1112.
Köhler, G. & Milstein, C. (1975). Continuous cultures of fused cells secreting antibody of predefined specificity. Nature 256, 495–497.[CrossRef][Medline]
Laemmli, U. K. (1970). Cleavage of structural proteins during the assembly of the head of bacteriophage T4. Nature 227, 680–685.[CrossRef][Medline]
Nallapareddy, S. R., Qin, X., Weinstock, G. M., Höök, M. & Murray, B. E. (2000). Enterococcus faecalis adhesin, Ace, mediates attachment to extracellular matrix proteins collagen type IV and laminin as well as collagen type I. Infect Immun 68, 5218–5224.
Nallapareddy, S. R., Weinstock, G. M. & Murray, B. E. (2003). Clinical isolates of Enterococcus faecium exhibit strain-specific collagen binding mediated by Acm, a new member of the MSCRAMM family. Mol Microbiol 47, 1733–1747.[CrossRef][Medline]
Nilsson, I. M., Patti, J. M., Bremell, T., Höök, M. & Tarkowski, A. (1998). Vaccination with a recombinant fragment of collagen adhesin provides protection against Staphylococcus aureus-mediated septic death. J Clin Invest 101, 2640–2649.[Medline]
Nitsche, D. P., Johansson, H. M., Frick, I.-M. & Mörgelin, M. (2006). Streptococcal protein FOG, a novel matrix adhesin interacting with collagen I in vivo. J Biol Chem 281, 1670–1679.
Nummelin, H., Merckel, M. C., Leo, J. C., Lankinen, H., Skurnik, M. & Goldman, A. (2004). The Yersinia adhesin Yad collagen-binding domain structure is a novel left-handed parallel β-roll. EMBO J 23, 701–711.[CrossRef][Medline]
Patti, J. M., Jonsson, H., Guss, B., Switalski, L. M., Wiberg, K., Lindberg, M. & Höök, M. (1992). Molecular characterization and expression of a gene encoding a Staphylococcus aureus collagen adhesin. J Biol Chem 267, 4766–4772.
Patti, J. M., Boles, J. O. & Höök, M. (1993). Identification and biochemical characterization of the ligand binding domain of the collagen adhesin from Staphylococcus aureus. Biochemistry 32, 11428–11435.[CrossRef][Medline]
Reese, C. A. & Mayne, R. (1981). Minor collagens of chicken hyaline cartilage. Biochemistry 20, 5443–5448.[CrossRef][Medline]
Rich, R. L., Demeler, B., Ashby, K., Deivanayagam, C. C., Petrich, J. W., Patti, J. M., Narayana, S. V. & Höök, M. (1998). Domain structure of the Staphylococcus aureus collagen adhesin. Biochemistry 37, 15423–15433.[CrossRef][Medline]
Rich, R. L., Kreikemeyer, B., Owens, R. T., LaBrenz, S., Narayana, S. V., Weinstock, G. M., Murray, B. E. & Höök, M. (1999). Ace is a collagen-binding MSCRAMM from Enterococcus faecalis. J Biol Chem 274, 26939–26945.
Roche, F. M., Downer, R., Keane, F., Speziale, P., Park, P. W. & Foster, T. J. (2004). The N-terminal A domain of fibronectin-binding proteins A and B promotes adhesion of Staphylococcus aureus to elastin. J Biol Chem 279, 38433–38440.
Rossi, A., Vitellaro-Zuccarello, L., Zanaboni, G., Monzani, E., Dyne, K. M., Cetta, G. & Tenni, R. (1996). Type I collagen CNBr peptides: species and behavior in solution. Biochemistry 35, 6048–6057.[CrossRef][Medline]
Schaufuss, P., Sting, R. & Lämmler, C. (1989). Isolation and characterization of an extracellular protease of Actinomyces pyogenes. Zentralbl Bakteriol 271, 452–459.[Medline]
Shimoji, Y., Ogawa, Y., Osaki, M., Kabeya, H., Maruyama, S., Mikami, T. & Sekizaki, T. (2003). Adhesive surface proteins of Erysipelothrix rhusiopathiae bind to polystyrene, fibronectin, and type I and IV collagens. J Bacteriol 185, 2739–2748.
Visai, L., Xu, Y., Casolini, F., Rindi, S., Höök, M. & Speziale, P. (2000). Monoclonal antibodies to CNA, a collagen-binding microbial surface component recognizing adhesive matrix molecules, detach Staphylococcus aureus from a collagen substrate. J Biol Chem 275, 39837–39845.
Vuento, M. & Vaheri, A. (1979). Purification of fibronectin from human plasma by affinity chromatography under non-denaturing conditions. Biochem J 183, 331–337.[Medline]
Walsh, E. J., O'Brien, L. M., Liang, X., Höök, M. & Foster, T. J. (2004). Clumping factor B, a fibrinogen-binding MSCRAMM (microbial surface components recognizing adhesive matrix molecules) adhesin of Staphylococcus aureus also binds to the tail region of type I cytokeratin 10. J Biol Chem 279, 50691–50699.
Xu, Y., Rivas, J. M., Brown, E. L., Liang, X. & Höök, M. (2004a). Virulence potential of the staphylococcal adhesin CNA in experimental arthritis is determined by its affinity for collagen. J Infect Dis 189, 2323–2333.[CrossRef][Medline]
Xu, Y., Liang, X., Chen, Y., Koehler, T. M. & Höök, M. (2004b). Identification and biochemical characterization of two novel collagen-binding MSCRAMMs of Bacillus anthracis. J Biol Chem 279, 51760–51768.
Zong, Y., Xu, Y., Liang, X., Keene, D. R., Höök, A., Gurusiddappa, S., Höök, M. & Narayana, S. V. (2005). A ‘Collagen Hug’ model for Staphylococcus aureus CNA binding to collagen. EMBO J 24, 4224–4236.[CrossRef][Medline]
Received 24 April 2007;
revised 26 June 2007;
accepted 26 June 2007.
| ||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||
| HOME | HELP | FEEDBACK | SUBSCRIPTIONS | ARCHIVE | SEARCH | TABLE OF CONTENTS |
| INT J SYST EVOL MICROBIOL | MICROBIOLOGY | J GEN VIROL |
| J MED MICROBIOL | ALL SGM JOURNALS | |
