Human Lactoferrin Binds and Removes the Hemoglobin Receptor Protein of the Periodontopathogen Porphyromonas gingivalis

Abstract

Porphyromonas gingivalis possesses a hemoglobin receptor (HbR) protein on the cell surface as one of the major components of the hemoglobin utilization system in this periodontopathogenic bacterium. HbR is intragenically encoded by the genes of an arginine-specific cysteine proteinase (rgpA), lysine-specific cysteine proteinase (kgp), and a hemagglutinin (hagA). Here, we have demonstrated that human lactoferrin as well as hemoglobin have the abilities to bind purified HbR and the cell surface of P. gingivalis through HbR. The interaction of lactoferrin with HbR led to the release of HbR from the cell surface of P. gingivalis. This lactoferrin-mediated HbR release was inhibited by the cysteine proteinase inhibitors effective to the cysteine proteinases of P. gingivalis. P. gingivalis could not utilize lactoferrin for its growth as an iron source and, in contrast, lactoferrin inhibited the growth of the bacterium in a rich medium containing hemoglobin as the sole iron source. Lactoferricin B, a 25-amino acid-long peptide located at the N-lobe of bovine lactoferrin, caused the same effects on P. gingivalis cells as human lactoferrin, indicating that the effects of lactoferrin might be attributable to the lactoferricin region. These results suggest that lactoferrin has a bacteriostatic action on P. gingivalis by binding HbR, removing it from the cell surface, and consequently disrupting the iron uptake system from hemoglobin. Porphyromonas gingivalis possesses a hemoglobin receptor (HbR) protein on the cell surface as one of the major components of the hemoglobin utilization system in this periodontopathogenic bacterium. HbR is intragenically encoded by the genes of an arginine-specific cysteine proteinase (rgpA), lysine-specific cysteine proteinase (kgp), and a hemagglutinin (hagA). Here, we have demonstrated that human lactoferrin as well as hemoglobin have the abilities to bind purified HbR and the cell surface of P. gingivalis through HbR. The interaction of lactoferrin with HbR led to the release of HbR from the cell surface of P. gingivalis. This lactoferrin-mediated HbR release was inhibited by the cysteine proteinase inhibitors effective to the cysteine proteinases of P. gingivalis. P. gingivalis could not utilize lactoferrin for its growth as an iron source and, in contrast, lactoferrin inhibited the growth of the bacterium in a rich medium containing hemoglobin as the sole iron source. Lactoferricin B, a 25-amino acid-long peptide located at the N-lobe of bovine lactoferrin, caused the same effects on P. gingivalis cells as human lactoferrin, indicating that the effects of lactoferrin might be attributable to the lactoferricin region. These results suggest that lactoferrin has a bacteriostatic action on P. gingivalis by binding HbR, removing it from the cell surface, and consequently disrupting the iron uptake system from hemoglobin. hemoglobin receptor Arg-gingipain Lys-gingipain lipopolysaccharide brain heart infusion Nα-p-tosyl-l-lysine chloromethyl ketone phenylmethylsulfonyl fluoride horseradish peroxidase phosphate-buffered saline Tris-buffered saline hemagglutinin response unit polyacrylamide gel electrophoresis Pathogenic bacteria have developed various strategies for acquiring iron from their hosts to support their growth, including production of siderophores to chelate iron ions from their environment and presentation of receptors to acquire iron and heme from iron- and heme-containing proteins such as transferrin, lactoferrin, and hemoglobin (1Bagg A. Neilands J.B. Microbiol. Rev. 1987; 51: 509-518Crossref PubMed Google Scholar, 2Guerinot M.L. Annu. Rev. Microbiol. 1994; 48: 743-772Crossref PubMed Scopus (527) Google Scholar, 3Schryvers A.B. Stojiljkovic I. Mol. Microbiol. 1999; 32: 1117-1123Crossref PubMed Scopus (201) Google Scholar). Porphyromonas gingivalis is a highly proteolytic Gram-negative anaerobic bacterium that is implicated as one of the major causative pathogens for advanced adult periodontitis (4Haffajee A.D. Socransky S.S. Periodontol. 2000. 1994; 5: 78-111Crossref PubMed Scopus (1202) Google Scholar). Heme is required for its growth (5Gibbons R.J. MacDonald J.B. J. Bacteriol. 1960; 80: 164-170Crossref PubMed Google Scholar, 6Shah H.N. Bonnett R. Mateen B. Williams R.A.D. Biochem. J. 1979; 180: 45-50Crossref PubMed Scopus (70) Google Scholar, 7Smalley J.W. Silver J. Marsh P.D. Birss A.J. Biochem. J. 1998; 331: 681-685Crossref PubMed Scopus (99) Google Scholar). So far it has not been reported that P. gingivalis produces siderophore (8Bramanti T.E. Holt S.C. Biochem. Biophys. Res. Commun. 1990; 166: 1146-1154Crossref PubMed Scopus (42) Google Scholar); rather, this bacterium elaborates a hemoglobin receptor (HbR)1 for acquisition of iron from hemoglobin (9Fujimura S. Shibata Y. Hirai K. Nakamura T. FEMS Immunol. Med. Microbiol. 1995; 10: 109-114Crossref PubMed Google Scholar, 10Fujimura S. Shibata Y. Hirai K. Nakamura T. Infect. Immun. 1996; 64: 2339-2342Crossref PubMed Google Scholar). HbR, a 19-kilodalton protein, was intragenically encoded by an arginine-specific cysteine proteinase (Arg-gingipain, RGP)-encoding gene (rgpA), a lysine-specific cysteine proteinase (Lys-gingipain, KGP)-encoding gene (kgp), and a hemagglutinin (HA)-encoding gene (hagA) (11Nakayama K. Ratnayake D.B. Tsukuba T. Kadowaki T. Yamamoto K. Fujimura S. Mol. Microbiol. 1998; 27: 51-61Crossref PubMed Scopus (100) Google Scholar). Several pieces of evidence show that HbR forms a large proteinase-adhesin complex with RGP, KGP, and HA proteins that are encoded intragenically by these genes (12Pavloff N. Potempa J. Pike R.N. Prochazka V. Kiefer M.C. Travis J. Barr P.J. J. Biol. Chem. 1995; 270: 1007-1010Abstract Full Text Full Text PDF PubMed Scopus (164) Google Scholar, 13Slakeski N. Bhogal P.S. O'Brien-Simpson N.M. Reynolds E.C. Microbiol. 1998; 144: 1583-1592Crossref PubMed Scopus (58) Google Scholar), and appears to be associated with a lipid A portion of lipopolysaccharide (LPS) (14Sharp L. Poole S. Reddi K. Fletcher J. Nair S. Wilson B. P. 1998; 144: PubMed Scopus Google gingivalis has gene it not HbR HA K. Microbiol. Immunol. PubMed Scopus Google Scholar). in a (11Nakayama K. Ratnayake D.B. Tsukuba T. Kadowaki T. Yamamoto K. Fujimura S. Mol. Microbiol. 1998; 27: 51-61Crossref PubMed Scopus (100) Google that a purified HbR protein has the to bind hemoglobin. with the and that to HbR on their cell that HbR was for P. gingivalis cells to bind hemoglobin Y. Ratnayake D.B. K. N. Yamamoto K. K. J. Biol. Chem. 1999; Full Text Full Text PDF PubMed Scopus Google Scholar). These that HbR is a major for the iron system from hemoglobin in P. is an protein in and PubMed Scopus Google Scholar). is from and the of the and of J. Med. PubMed Scopus Google Scholar, R. PubMed Google Scholar, Med. PubMed Scopus Google Scholar, J. PubMed Scopus Google Scholar, A. J. Med. PubMed Scopus Google Scholar). Several for the action of lactoferrin have been lactoferrin has the to chelate results in of growth B. J. 5: Google Scholar). it has been that a peptide is from lactoferrin by with has a This peptide of the N-lobe of the surface of a lactoferrin is from the iron binding K. K. Biophys. PubMed Scopus Google Scholar, K. Infect. Immun. PubMed Google Scholar, R. 1996; PubMed Scopus Google Scholar). The of action of this peptide be to as in such as and that the peptide with binding on cell such as these and to the uptake of the The forms a in of and cell A. PubMed Scopus Google Scholar, T. 1994; PubMed Scopus Google Scholar). it has been demonstrated that lactoferrin of and the of this bacterium J. J.W. S. A. 1998; PubMed Scopus Google of lactoferrin to as as in the of with and adult periodontitis J. Periodontol. PubMed Scopus Google Scholar, J. Periodontol. PubMed Scopus (58) Google Scholar). P. gingivalis cells have the to lactoferrin S. S. A. Microbiol. Immunol. PubMed Scopus Google Scholar), it is not on the cell surface for this it has not been P. gingivalis cells utilize iron from lactoferrin lactoferrin their growth as an the that human lactoferrin to HbR and it from the cell surface of P. gingivalis and that the lactoferricin of lactoferrin and the of HbR might be for the interaction of lactoferrin with HbR. that lactoferrin could not support the growth of P. gingivalis as an iron source. contrast, the growth of P. gingivalis was inhibited by lactoferrin it was in a rich medium containing hemoglobin as the sole iron P. gingivalis well in a medium containing hemoglobin as an iron the of hemoglobin required to support its growth is that of The of and hemoglobin to support of the growth are and S. K. K. T. A. FEMS Microbiol. 1995; PubMed Google Scholar), that the iron from and hemoglobin at in a (11Nakayama K. Ratnayake D.B. Tsukuba T. Kadowaki T. Yamamoto K. Fujimura S. Mol. Microbiol. 1998; 27: 51-61Crossref PubMed Scopus (100) Google Scholar), we a of the iron from that P. gingivalis cells to by the HA proteins intragenically encoded by and this the proteinases surface proteins of in the release of hemoglobin. hemoglobin be by the HbR proteins and to release The heme be on the of P. gingivalis cells and by the bacterium. HbR was to be the major hemoglobin receptor protein in P. gingivalis Y. Ratnayake D.B. K. N. Yamamoto K. K. J. Biol. Chem. 1999; Full Text Full Text PDF PubMed Scopus Google Scholar). that a protein, the to the interaction of hemoglobin with HbR by a by surface with an was reported that the growth of P. gingivalis in a medium containing hemoglobin S. K. K. T. A. FEMS Microbiol. 1995; PubMed Google Scholar). These results suggest that HbR a in the acquisition of iron from hemoglobin in a for P. this we that lactoferrin, as well as HbR. is to a in the of in the and its to iron from pathogens has been as an B. J. 5: Google Scholar). The of lactoferrin not be of the of iron ions from the environment the interaction lactoferrin and cell of P. R. N. PubMed Scopus Google Scholar). lactoferrin to the cell surface of P. gingivalis. The results with the various the suggest that lactoferrin binding to the cell surface is attributable to the of HbR. The has HbR on the cell the of the cells to is that of the Y. Ratnayake D.B. K. N. Yamamoto K. K. J. Biol. Chem. 1999; Full Text Full Text PDF PubMed Scopus Google Scholar). lactoferrin binding of the be by the that the HbR on the cell surface of the are from of HbR from the and and this the of lactoferrin to HbR HbR in the from the HbR with the proteins of such as and of A.B. R. Med. Biol. 1998; PubMed Scopus Google that lactoferrin the growth of P. gingivalis in the medium containing hemoglobin as the sole iron source not in the medium containing Gram-negative lactoferrin their and from the cells B. Med. Biol. 1998; PubMed Scopus Google Scholar). P. release of the HA proteins was lactoferrin the in the of P. gingivalis. contrast, lactoferrin HbR from P. gingivalis J. J.W. S. A. 1998; PubMed Scopus Google that human lactoferrin proteinase from the cell surface of and and that the and the proteinase and are as large and K. J. Infect. Immun. PubMed Google Scholar, J. R. K. 1987; PubMed Scopus Google Scholar, M.L. J.W. Mol. Microbiol. PubMed Scopus Google Scholar). the and gene of the proteolytic proteins and HbR, and we the proteolytic of lactoferrin was in the release of HbR from the cell The results that not the lactoferrin-mediated HbR and a of and that the to and proteinases the HbR HbR a complex with proteinase and HA and these are to one in the of growth Microbiol. Immunol. PubMed Scopus Google Scholar). this these are by and proteinases the proteins associated (12Pavloff N. Potempa J. Pike R.N. Prochazka V. Kiefer M.C. Travis J. Barr P.J. J. Biol. Chem. 1995; 270: 1007-1010Abstract Full Text Full Text PDF PubMed Scopus (164) Google Scholar, Microbiol. Immunol. PubMed Scopus Google Scholar, P.S. N. Reynolds E.C. Microbiol. PubMed Scopus Google Scholar). the of the proteinase inhibitors on the lactoferrin-mediated HbR release be to the of and proteinase that results in of of the this the HbR the to be from the HbR from the as by the that the HbR lactoferrin at a of on the HbR in a interaction lactoferrin and HbR the HbR that lactoferrin not bind the HbR in the including and that the growth and HbR release by of lactoferricin as well as These results suggest that the lactoferricin of lactoferrin with the of HbR in an the HbR and components of the and release HbR from the cell surface The of the proteinase inhibitors on the HbR release that a of the proteinase be by the is required in the of HbR we the that lactoferrin with the proteolytic proteins components of the complex in to HbR. this it is that proteinase inhibitors such as and of P. gingivalis appears to be attributable to the HA proteins of the complex Y. Microbiol. Immunol. PubMed Google Scholar, J. Microbiol. PubMed Scopus Google Scholar, R.N. Potempa J. Travis J. J. Bacteriol. 1996; PubMed Google of P. gingivalis by lactoferrin on the of P. gingivalis cells to a in the medium with large of lactoferrin, lactoferrin was by proteinases from P. gingivalis and its bacteriostatic The lactoferrin-mediated growth was not in the medium containing of hemoglobin. the in growth of P. gingivalis be a of the interaction of lactoferrin with HbR, is the major hemoglobin receptor of the bacterium. These results suggest that lactoferrin the of P. gingivalis by removing HbR from the cell surface and disrupting the iron acquisition system for the in of the bacterium and that and and proteinases as lactoferrin Pathogenic bacteria have developed various strategies for acquiring iron from their hosts to support their growth, including production of siderophores to chelate iron ions from their environment and presentation of receptors to acquire iron and heme from iron- and heme-containing proteins such as transferrin, lactoferrin, and hemoglobin (1Bagg A. Neilands J.B. Microbiol. Rev. 1987; 51: 509-518Crossref PubMed Google Scholar, 2Guerinot M.L. Annu. Rev. Microbiol. 1994; 48: 743-772Crossref PubMed Scopus (527) Google Scholar, 3Schryvers A.B. Stojiljkovic I. Mol. Microbiol. 1999; 32: 1117-1123Crossref PubMed Scopus (201) Google Scholar). Porphyromonas gingivalis is a highly proteolytic Gram-negative anaerobic bacterium that is implicated as one of the major causative pathogens for advanced adult periodontitis (4Haffajee A.D. Socransky S.S. Periodontol. 2000. 1994; 5: 78-111Crossref PubMed Scopus (1202) Google Scholar). Heme is required for its growth (5Gibbons R.J. MacDonald J.B. J. Bacteriol. 1960; 80: 164-170Crossref PubMed Google Scholar, 6Shah H.N. Bonnett R. Mateen B. Williams R.A.D. Biochem. J. 1979; 180: 45-50Crossref PubMed Scopus (70) Google Scholar, 7Smalley J.W. Silver J. Marsh P.D. Birss A.J. Biochem. J. 1998; 331: 681-685Crossref PubMed Scopus (99) Google Scholar). So far it has not been reported that P. gingivalis produces siderophore (8Bramanti T.E. Holt S.C. Biochem. Biophys. Res. Commun. 1990; 166: 1146-1154Crossref PubMed Scopus (42) Google Scholar); rather, this bacterium elaborates a hemoglobin receptor (HbR)1 for acquisition of iron from hemoglobin (9Fujimura S. Shibata Y. Hirai K. Nakamura T. FEMS Immunol. Med. Microbiol. 1995; 10: 109-114Crossref PubMed Google Scholar, 10Fujimura S. Shibata Y. Hirai K. Nakamura T. Infect. Immun. 1996; 64: 2339-2342Crossref PubMed Google Scholar). HbR, a 19-kilodalton protein, was intragenically encoded by an arginine-specific cysteine proteinase (Arg-gingipain, RGP)-encoding gene (rgpA), a lysine-specific cysteine proteinase (Lys-gingipain, KGP)-encoding gene (kgp), and a hemagglutinin (HA)-encoding gene (hagA) (11Nakayama K. Ratnayake D.B. Tsukuba T. Kadowaki T. Yamamoto K. Fujimura S. Mol. Microbiol. 1998; 27: 51-61Crossref PubMed Scopus (100) Google Scholar). Several pieces of evidence show that HbR forms a large proteinase-adhesin complex with RGP, KGP, and HA proteins that are encoded intragenically by these genes (12Pavloff N. Potempa J. Pike R.N. Prochazka V. Kiefer M.C. Travis J. Barr P.J. J. Biol. Chem. 1995; 270: 1007-1010Abstract Full Text Full Text PDF PubMed Scopus (164) Google Scholar, 13Slakeski N. Bhogal P.S. O'Brien-Simpson N.M. Reynolds E.C. Microbiol. 1998; 144: 1583-1592Crossref PubMed Scopus (58) Google Scholar), and appears to be associated with a lipid A portion of lipopolysaccharide (LPS) (14Sharp L. Poole S. Reddi K. Fletcher J. Nair S. Wilson B. P. 1998; 144: PubMed Scopus Google gingivalis has gene it not HbR HA K. Microbiol. Immunol. PubMed Scopus Google Scholar). in a (11Nakayama K. Ratnayake D.B. Tsukuba T. Kadowaki T. Yamamoto K. Fujimura S. Mol. Microbiol. 1998; 27: 51-61Crossref PubMed Scopus (100) Google that a purified HbR protein has the to bind hemoglobin. with the and that to HbR on their cell that HbR was for P. gingivalis cells to bind hemoglobin Y. Ratnayake D.B. K. N. Yamamoto K. K. J. Biol. Chem. 1999; Full Text Full Text PDF PubMed Scopus Google Scholar). These that HbR is a major for the iron system from hemoglobin in P. gingivalis. is an protein in and PubMed Scopus Google Scholar). is from and the of the and of J. Med. PubMed Scopus Google Scholar, R. PubMed Google Scholar, Med. PubMed Scopus Google Scholar, J. PubMed Scopus Google Scholar, A. J. Med. PubMed Scopus Google Scholar). Several for the action of lactoferrin have been lactoferrin has the to chelate results in of growth B. J. 5: Google Scholar). it has been that a peptide is from lactoferrin by with has a This peptide of the N-lobe of the surface of a lactoferrin is from the iron binding K. K. Biophys. PubMed Scopus Google Scholar, K. Infect. Immun. PubMed Google Scholar, R. 1996; PubMed Scopus Google Scholar). The of action of this peptide be to as in such as and that the peptide with binding on cell such as these and to the uptake of the The forms a in of and cell A. PubMed Scopus Google Scholar, T. 1994; PubMed Scopus Google Scholar). it has been demonstrated that lactoferrin of and the of this bacterium J. J.W. S. A. 1998; PubMed Scopus Google Scholar). The of lactoferrin to as as in the of with and adult periodontitis J. Periodontol. PubMed Scopus Google Scholar, J. Periodontol. PubMed Scopus (58) Google Scholar). P. gingivalis cells have the to lactoferrin S. S. A. Microbiol. Immunol. PubMed Scopus Google Scholar), it is not on the cell surface for this it has not been P. gingivalis cells utilize iron from lactoferrin lactoferrin their growth as an the that human lactoferrin to HbR and it from the cell surface of P. gingivalis and that the lactoferricin of lactoferrin and the of HbR might be for the interaction of lactoferrin with HbR. that lactoferrin could not support the growth of P. gingivalis as an iron source. contrast, the growth of P. gingivalis was inhibited by lactoferrin it was in a rich medium containing hemoglobin as the sole iron source. P. gingivalis well in a medium containing hemoglobin as an iron the of hemoglobin required to support its growth is that of The of and hemoglobin to support of the growth are and S. K. K. T. A. FEMS Microbiol. 1995; PubMed Google Scholar), that the iron from and hemoglobin at in a (11Nakayama K. Ratnayake D.B. Tsukuba T. Kadowaki T. Yamamoto K. Fujimura S. Mol. Microbiol. 1998; 27: 51-61Crossref PubMed Scopus (100) Google Scholar), we a of the iron from that P. gingivalis cells to by the HA proteins intragenically encoded by and this the proteinases surface proteins of in the release of hemoglobin. hemoglobin be by the HbR proteins and to release The heme be on the of P. gingivalis cells and by the bacterium. HbR was to be the major hemoglobin receptor protein in P. gingivalis Y. Ratnayake D.B. K. N. Yamamoto K. K. J. Biol. Chem. 1999; Full Text Full Text PDF PubMed Scopus Google Scholar). that a protein, the to the interaction of hemoglobin with HbR by a by surface with an was reported that the growth of P. gingivalis in a medium containing hemoglobin S. K. K. T. A. FEMS Microbiol. 1995; PubMed Google Scholar). These results suggest that HbR a in the acquisition of iron from hemoglobin in a for P. this we that lactoferrin, as well as HbR. is to a in the of in the and its to iron from pathogens has been as an B. J. 5: Google Scholar). The of lactoferrin not be of the of iron ions from the environment the interaction lactoferrin and cell of P. R. N. PubMed Scopus Google Scholar). lactoferrin to the cell surface of P. gingivalis. The results with the various the suggest that lactoferrin binding to the cell surface is attributable to the of HbR. The has HbR on the cell the of the cells to is that of the Y. Ratnayake D.B. K. N. Yamamoto K. K. J. Biol. Chem. 1999; Full Text Full Text PDF PubMed Scopus Google Scholar). lactoferrin binding of the be by the that the HbR on the cell surface of the are from of HbR from the and and this the of lactoferrin to HbR HbR in the from the HbR with the proteins of such as and of A.B. R. Med. Biol. 1998; PubMed Scopus Google that lactoferrin the growth of P. gingivalis in the medium containing hemoglobin as the sole iron source not in the medium containing Gram-negative lactoferrin their and from the cells B. Med. Biol. 1998; PubMed Scopus Google Scholar). P. release of the HA proteins was lactoferrin the in the of P. gingivalis. contrast, lactoferrin HbR from P. gingivalis J. J.W. S. A. 1998; PubMed Scopus Google that human lactoferrin proteinase from the cell surface of and and that the and the proteinase and are as large and K. J. Infect. Immun. PubMed Google Scholar, J. R. K. 1987; PubMed Scopus Google Scholar, M.L. J.W. Mol. Microbiol. PubMed Scopus Google Scholar). the and gene of the proteolytic proteins and HbR, and we the proteolytic of lactoferrin was in the release of HbR from the cell The results that not the lactoferrin-mediated HbR and a of and that the to and proteinases the HbR HbR a complex with proteinase and HA and these are to one in the of growth Microbiol. Immunol. PubMed Scopus Google Scholar). this these are by and proteinases the proteins associated (12Pavloff N. Potempa J. Pike R.N. Prochazka V. Kiefer M.C. Travis J. Barr P.J. J. Biol. Chem. 1995; 270: 1007-1010Abstract Full Text Full Text PDF PubMed Scopus (164) Google Scholar, Microbiol. Immunol. PubMed Scopus Google Scholar, P.S. N. Reynolds E.C. Microbiol. PubMed Scopus Google Scholar). the of the proteinase inhibitors on the lactoferrin-mediated HbR release be to the of and proteinase that results in of of the this the HbR the to be from the HbR from the as by the that the HbR lactoferrin at a of on the HbR in a interaction lactoferrin and HbR the HbR that lactoferrin not bind the HbR in the including and that the growth and HbR release by of lactoferricin as well as These results suggest that the lactoferricin of lactoferrin with the of HbR in an the HbR and components of the and release HbR from the cell surface The of the proteinase inhibitors on the HbR release that a of the proteinase be by the is required in the of HbR we the that lactoferrin with the proteolytic proteins components of the complex in to HbR. this it is that proteinase inhibitors such as and of P. gingivalis appears to be attributable to the HA proteins of the complex Y. Microbiol. Immunol. PubMed Google Scholar, J. Microbiol. PubMed Scopus Google Scholar, R.N. Potempa J. Travis J. J. Bacteriol. 1996; PubMed Google of P. gingivalis by lactoferrin on the of P. gingivalis cells to a in the medium with large of lactoferrin, lactoferrin was by proteinases from P. gingivalis and its bacteriostatic The lactoferrin-mediated growth was not in the medium containing of hemoglobin. the in growth of P. gingivalis be a of the interaction of lactoferrin with HbR, is the major hemoglobin receptor of the bacterium. These results suggest that lactoferrin the of P. gingivalis by removing HbR from the cell surface and disrupting the iron acquisition system for the in of the bacterium and that and and proteinases as lactoferrin P. gingivalis well in a medium containing hemoglobin as an iron the of hemoglobin required to support its growth is that of The of and hemoglobin to support of the growth are and S. K. K. T. A. FEMS Microbiol. 1995; PubMed Google Scholar), that the iron from and hemoglobin at in a (11Nakayama K. Ratnayake D.B. Tsukuba T. Kadowaki T. Yamamoto K. Fujimura S. Mol. Microbiol. 1998; 27: 51-61Crossref PubMed Scopus (100) Google Scholar), we a of the iron from that P. gingivalis cells to by the HA proteins intragenically encoded by and this the proteinases surface proteins of in the release of hemoglobin. hemoglobin be by the HbR proteins and to release The heme be on the of P. gingivalis cells and by the bacterium. HbR was to be the major hemoglobin receptor protein in P. gingivalis Y. Ratnayake D.B. K. N. Yamamoto K. K. J. Biol. Chem. 1999; Full Text Full Text PDF PubMed Scopus Google Scholar). that a protein, the to the interaction of hemoglobin with HbR by a by surface with an was reported that the growth of P. gingivalis in a medium containing hemoglobin S. K. K. T. A. FEMS Microbiol. 1995; PubMed Google Scholar). These results suggest that HbR a in the acquisition of iron from hemoglobin in a for P. gingivalis. this we that lactoferrin, as well as HbR. is to a in the of in the and its to iron from pathogens has been as an B. J. 5: Google Scholar). The of lactoferrin not be of the of iron ions from the environment the interaction lactoferrin and cell of P. R. N. PubMed Scopus Google Scholar). lactoferrin to the cell surface of P. gingivalis. The results with the various the suggest that lactoferrin binding to the cell surface is attributable to the of HbR. The has HbR on the cell the of the cells to is that of the Y. Ratnayake D.B. K. N. Yamamoto K. K. J. Biol. Chem. 1999; Full Text Full Text PDF PubMed Scopus Google Scholar). lactoferrin binding of the be by the that the HbR on the cell surface of the are from of HbR from the and and this the of lactoferrin to HbR HbR in the from the HbR with the proteins of such as and of A.B. R. Med. Biol. 1998; PubMed Scopus Google Scholar). that lactoferrin the growth of P. gingivalis in the medium containing hemoglobin as the sole iron source not in the medium containing Gram-negative lactoferrin their and from the cells B. Med. Biol. 1998; PubMed Scopus Google Scholar). P. release of the HA proteins was lactoferrin the in the of P. gingivalis. contrast, lactoferrin HbR from P. gingivalis J. J.W. S. A. 1998; PubMed Scopus Google that human lactoferrin proteinase from the cell surface of and and that the and the proteinase and are as large and K. J. Infect. Immun. PubMed Google Scholar, J. R. K. 1987; PubMed Scopus Google Scholar, M.L. J.W. Mol. Microbiol. PubMed Scopus Google Scholar). the and gene of the proteolytic proteins and HbR, and we the proteolytic of lactoferrin was in the release of HbR from the cell The results that not the lactoferrin-mediated HbR and a of and that the to and proteinases the HbR HbR a complex with proteinase and HA and these are to one in the of growth Microbiol. Immunol. PubMed Scopus Google Scholar). this these are by and proteinases the proteins associated (12Pavloff N. Potempa J. Pike R.N. Prochazka V. Kiefer M.C. Travis J. Barr P.J. J. Biol. Chem. 1995; 270: 1007-1010Abstract Full Text Full Text PDF PubMed Scopus (164) Google Scholar, Microbiol. Immunol. PubMed Scopus Google Scholar, P.S. N. Reynolds E.C. Microbiol. PubMed Scopus Google Scholar). the of the proteinase inhibitors on the lactoferrin-mediated HbR release be to the of and proteinase that results in of of the this the HbR the to be from the HbR from the as by the that the HbR lactoferrin at a of on the HbR in a interaction lactoferrin and HbR the HbR that lactoferrin not bind the HbR in the including and that the growth and HbR release by of lactoferricin as well as These results suggest that the lactoferricin of lactoferrin with the of HbR in an the HbR and components of the and release HbR from the cell surface The of the proteinase inhibitors on the HbR release that a of the proteinase be by the is required in the of HbR we the that lactoferrin with the proteolytic proteins components of the complex in to HbR. this it is that proteinase inhibitors such as and of P. gingivalis appears to be attributable to the HA proteins of the complex Y. Microbiol. Immunol. PubMed Google Scholar, J. Microbiol. PubMed Scopus Google Scholar, R.N. Potempa J. Travis J. J. Bacteriol. 1996; PubMed Google Scholar). of P. gingivalis by lactoferrin on the of P. gingivalis cells to a in the medium with large of lactoferrin, lactoferrin was by proteinases from P. gingivalis and its bacteriostatic The lactoferrin-mediated growth was not in the medium containing of hemoglobin. the in growth of P. gingivalis be a of the interaction of lactoferrin with HbR, is the major hemoglobin receptor of the bacterium. These results suggest that lactoferrin the of P. gingivalis by removing HbR from the cell surface and disrupting the iron acquisition system for the in of the bacterium and that and and proteinases as lactoferrin and R. for the of and by K. is with