Mechanism of formation of sulphhaemoglobin

Upregulation and Mitochondrial Sequestration of Hemoglobin Occur in Circulating Leukocytes during Critical Illness, Conferring a Cytoprotective Phenotype

“…Similarly, with respect to the interactions of Hbs with oxyradicals, substantial work has been conducted already, which can be reviewed in the literature (37)(38)(39). With respect to the interactions of Hbs with H 2 S, several lines of studies have demonstrated the formation of sulfhemoglobins (40,41), and Banerjee and colleagues have recently outlined several novel aspects of the interaction, especially with respect to the interactions of H 2 S with methemoglobin (42).…”

Sulfide-hemoglobin interactions in the sulfide-tolerant salt marsh resident, the California killifish Fundulus parvipinnis

“…The purity and concentration of SHb solutions may be determined using the ratio A620: A,,, = 2.6 for a 100% pure deoxygenated SHh sample, and an extinction coefficient of 21.5 mmol-I ' 1 . cm-' at 620 nm (Nichol et al 1968: Carrico et al 1978b: Brittain 1981. Marchant et al (1974) used A,,,/A,,,, with ratios greater than 2 indicating 80% punty or better Other methods of SHb measurement have also been described by Evelyn and Malloy (1938) and Dijkhuizen et ai.…”

“…It should be noted that the above categories are not mutually exclusive. SHb formation is a form of immobilization, where sulfide adds across a pyrrole double bond in the porphyrin as an episulfide (Morel1 et al 1967;Nichol et al 1968;Berzofsky et al 1972;Brittain et al 1982). Formation of ferric hemoglobin-sulfide complex likewise immobilizes sulfide, but the complex is unstable and eventually yields an oxidized sulfur product (Coryell et al 1937).…”

Sulfide Oxidation by a Noncanonical Pathway in Red Blood Cells Generates Thiosulfate and Polysulfides

“…The reaction of sulfide with Hb was first reported in 1863 under conditions that led to the formation of sulfhemoglobin, with a characteristic green color (13). This reaction is observed with oxyferrous Hb, results in covalent modification of the tetrapyrrole (14), and is not pertinent to catalytic sulfide oxidation. Stoichiometric binding of H 2 S to ferric or methemoglobin (MetHb) to give sulfide-MetHb was first reported in 1933 (15).…”