Open AccessMitochondrial Sulfide Oxidation in Arenicola Marina
Author(s) -
Völkel Susanne,
Grieshaber Manfred K.
Publication year - 1996
Publication title -
european journal of biochemistry
Language(s) - English
Resource type - Journals
eISSN - 1432-1033
pISSN - 0014-2956
DOI - 10.1111/j.1432-1033.1996.00231.x
Subject(s) - sulfide , thiosulfate , antimycin a , alternative oxidase , chemistry , salicylhydroxamic acid , cyanide , respiratory chain , cytochrome c oxidase , electron transport chain , biochemistry , mitochondrion , inorganic chemistry , organic chemistry , enzyme , sulfur
Sulfide is oxidized in the mitochondria of the lugworm Arenicola marina. Mitochondrial sulfide oxidation is coupled with oxygen consumption and with an equimolar production of thiosulfate [Vökel, S. & Grieshaber, M. K. (1994) Mar. Biol. 118 , 137–147], Mitochondrial respiration in the presence of malate (or succinate) and ADP but without sulfide could be completely inhibited by rotenone, antimycin, cyanide, and sulfide. Only 40% inhibition was achieved by salicylhydroxamic acid. Sulfide oxidation (with sulfide as the only substrate) was fully inhibited by antimycin and by salicylhydroxamic acid but not by rotenone or sulfide. Moreover, sulfide oxidation was 3–4‐fold less sensitive to cyanide as compared to normal respiration. The data indicate that sulfide oxidation in A. marina is linked to the respiratory electron transport chain. We suggest that electrons from sulfide enter the respiratory chain via ubiquinone or at the ubiquinol–cytochrome‐ c oxidoreductase. At sulfide concentrations higher than 10 μM, the cyto‐chrome‐ c oxidase is blocked and electrons from sulfide are transferred to oxygen via an alternative terminal oxidase.