Lipid-free apolipoprotein A-I exerts an antioxidative role against cell-free hemoglobin.

ABSTRACT: Cell-free hemoglobin (Hb) resulting from hemolysis is redox-active. It disrupts the oxidoreducing microenvironment, shifting the balance unfavorably towards tissue cytotoxicity. Thus, immediate suppression of the Hb-redox activity and removal of the cell-free plasma Hb is vital for maintaining homeostasis and survival. Among several known Hb-binding plasma proteins, haptoglobin (Hp) is the primary antioxidant of Hb. However, Hb-mediated oxidative stress persists in the covalently bound Hb-Hp aggregates or when Hp is depleted during a severe hemolysis. We therefore inquired whether there is an alternative anti-oxidative defense tactic in the blood. Here, we identified an Hb-interactome in the plasma, constituting Hb, Hp and lipid-free apolipoprotein A-I (apoAI). We found that apoAI acts rap

SUBMITTER: Du R 

PROVIDER: S-EPMC3714184 | biostudies-literature | 2012

REPOSITORIES: biostudies-literature