Metabolism
Sulfide Oxidation by a Noncanonical Pathway in Red Blood Cells Generates Thiosulfate and Polysulfides
Background: RBCs produce H2S but, lacking mitochondria, are devoid of the canonical sulfide oxidation pathway.Results: RBCs utilize methemoglobin to catalyze H2S oxidation producing thiosulfate and polysulfide.Conclusion: In the presence of NADPH and a reductase, ferric sulfide hemoglobin is converted to oxyhemoglobin, completing the sulfide oxidation cycle.Significance: We describe a novel mechanism for H2S oxidation that may be pertinent to other hemeproteins.
