Identification of the receptor scavenging hemopexin-heme complexes.

Identification of the Receptor Scavenging Hemopexin- Heme Complexes Running title: Identification of the Hemopexin-Heme Receptor

RED CELLS Identification of the receptor scavenging hemopexin-heme complexes

Heme released from heme-binding proteins on internal hemorrhage, hemolysis, myolysis, or other cell damage is highly toxic due to oxidative and proinflammatory effects. Complex formation with hemopexin, the high-affinity heme-binding protein in plasma and cerebrospinal fluid, dampens these effects and is suggested to facilitate cellular heme metabolism. Using a ligand-affinity approach, we puri...

Heme-Hemopexin Scavenging Is Active in the Brain and Associates With Outcome After Subarachnoid Hemorrhage.

BACKGROUND AND PURPOSE Long-term outcome after subarachnoid hemorrhage (SAH) is potentially linked to cytotoxic heme. Free heme is bound by hemopexin and rapidly scavenged by CD91. We hypothesized that heme scavenging in the brain would be associated with outcome after hemorrhage. METHODS Using cerebrospinal fluid and tissue from patients with SAH and control individuals, the activity of the ...

Regulation of heme oxygenase and metallothionein gene expression by the heme analogs, cobalt-, and tin-protoporphyrin.

Two heme analogs, cobalt- and tin-protoporphyrin (CoPP and SnPP, respectively) have been used to probe the heme-hemopexin interaction, hemopexin receptor binding, and the mechanism of regulation of heme oxygenase (HO) and metallothionein-1 (MT-1) gene expression by hemopexin. Both CoPP and SnPP are HO inhibitors and hemopexin binds SnPP (Morgan, W. T., Alam, J., Deaciuc, V., Muster, P., Tatum, ...

Binding of heme-hemopexin complexes by soluble HxuA protein allows utilization of this complexed heme by Haemophilus influenzae.

Utilization of heme-hemopexin as a source of heme by Haemophilus influenzae type b is dependent on expression by this bacterium of the 100-kDa HxuA protein, which is both present on the bacterial cell surface and released into the culture supernatant (L. D. Cope, R. Yogev, U. Muller-Eberhard, and E. J. Hansen, J. Bacteriol. 177:2644-2653, 1995). Radioimmunoprecipitation analysis showed that the...