FIG. 5.

Binding of hemoglobin (A) and human serum albumin-hemin complex (B) to P. gingivalis A7436 and mutant whole cells. P. gingivalis cells depleted of heme were used for either the spectrophotometric hemoglobin binding assay (A) or the ELISA HSA-Hm binding assay (B) as described in Materials and Methods. Data were analyzed using Student's t test and are shown as the mean ± standard deviation from at least three independent experiments, each performed in duplicate. **, P < 0.01; *, P < 0.05 (mutant strains versus wild-type strain). A7436, P. gingivalis wild-type strain; WS1, P. gingivalis hmuR::ermF; WS21, P. gingivalis hmuR^H95A; WS22, P. gingivalis hmuR^H434A; WS23, P. gingivalis hmuR^H95A,H434A; WS24, P. gingivalis hmuR^{YRAP420-423YAAA}; WS25, P. gingivalis hmuR^{NPDL442-445NAAA}; WS26, P. gingivalis ermF control.