Utilization of myoglobin as a heme source by Haemophilus influenzae requires binding of myoglobin to haptoglobin.
Haemophilus influenzae has an absolute growth requirement for heme. One potential in vivo source of heme is the protein myoglobin which is found at low levels in human serum. No tested H. influenzae strain was able to use myoglobin as a heme source. However, all strains were able to utilize the heme from myoglobin when myoglobin was complexed with haptoglobin. Utilization of the haptoglobin-myoglobin complex was shown to be mediated by the previously described hemoglobin/hemoglobin-haptoglobin-binding proteins of H. influenzae.
Morton
Daniel J
DJ
Department of Pediatrics, University of Oklahoma Health Sciences Center, Oklahoma City, OK 73104, USA.
Van Wagoner
Timothy M
TM
Seale
Thomas W
TW
Whitby
Paul W
PW
Stull
Terrence L
TL
D001426:Bacterial Proteins / Q000378:metabolism / Q000502:physiology; D006193:Haemophilus influenzae / Q000254:growth & development / Q000378:metabolism*; D006242:Haptoglobins / Q000378:metabolism*; D006418:Heme / Q000378:metabolism*; D006801:Humans; D009211:Myoglobin / Q000378:metabolism*
D001426:Bacterial Proteins; C485359:HP protein, human; D006242:Haptoglobins; D009211:Myoglobin; D006418:Heme