Table 2.

Binding of radiolabeled hemoglobin and hemoglobin-haptoglobin to wild-type and mutant strains

Passage in the presence of:Straincpm associated with cells
HemoglobinHemoglobin-haptoglobin
Hemoglobina N18212,506 ± 3,5513,746 ± 1,686
N182.1414,363 ± 1,8924,163 ± 318
N182.15558 ± 326503 ± 111
N182.1612,668 ± 9873,218 ± 331
N182.17114 ± 2859 ± 59
DH5α39 ± 271 ± 2
Hemeb N18214,382 ± 3,7153,991 ± 1,841
N182.1747 ± 397 ± 9
N182.11720 ± 112 ± 17
  • a Bacterial strains (for genotypes, see Table 1) were passaged twice on solidified medium containing hemoglobin (100 μg/ml) prior to heme starvation.

  • b Bacterial strains were passaged twice on solidified medium containing heme (50 μg/ml) prior to heme starvation.