Interaction of Porphyromonas gingivalis with transferrin.
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.
Tazaki
K
K
Department of Preventive Dentistry, Osaka University Faculty of Dentistry, Japan.
Inoshita
E
E
Amano
A
A
Hanioka
T
T
Tamagawa
H
H
Shizukuishi
S
S
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*
D003470:Culture Media; D014168:Transferrin; D007501:Iron