title: Interaction of Porphyromonas gingivalis with transferrin.
abstract: In this study, we characterized the binding of transferrin to Porphyromonas gingivalis using a classical receptor-binding assay, and examined the relationship between the binding and availability of transferrin for the growth of P. gingivalis. The binding of 125I-labeled human transferrin to P. gingivalis occurred rapidly, reversibly and specifically. Scatchard analysis yielded a Kd of 1.37 +/- 0.16 microM and an apparent number of 1.13 +/- 0.26 x 10(5) receptors per cell. The binding of transferrin was much increased when organisms were grown in iron-limited conditions. Among the species of black-pigmented anaerobic.rods, those strains of P. gingivalis which had high transferrin-binding activity exhibited unrestricted growth following the addition of transferrin to the hemin-free culture medium. On the other hand, the presence of transferrin in the culture medium did not support unrestricted growth of organisms that had low transferrin-binding activity. These results suggest that the binding of transferrin to P. gingivalis cells may be a preliminary step in iron acquisition, which allows them to survive in the healthy periodontal environment.
authors.affiliation: Department of Preventive Dentistry, Osaka University Faculty of Dentistry, Japan.
authors.forename: K
authors.initials: K
authors.lastname: Tazaki
authors.forename: E
authors.initials: E
authors.lastname: Inoshita
authors.forename: A
authors.initials: A
authors.lastname: Amano
authors.forename: T
authors.initials: T
authors.lastname: Hanioka
authors.forename: H
authors.initials: H
authors.lastname: Tamagawa
authors.forename: S
authors.initials: S
authors.lastname: Shizukuishi
mesh_terms: D000818:Animals; D016866:Bacteroidaceae Infections / Q000209:etiology; D002417:Cattle; D003470:Culture Media; D006801:Humans; D066298:In Vitro Techniques; D007501:Iron / Q000378:metabolism; D007700:Kinetics; D010510:Periodontal Diseases / Q000209:etiology; D016966:Porphyromonas gingivalis / Q000254:growth & development / Q000378:metabolism*; D011485:Protein Binding; D014168:Transferrin / Q000378:metabolism*
chemical_list: D003470:Culture Media; D014168:Transferrin; D007501:Iron