Action of DCCD on the H+ O stoichiometry of mitoplast cytochrome c oxidase

Albert L. Lehninger, Baltazar Reynafarje, Lidia Costa

Research output: Contribution to journalArticlepeer-review


The mechanistic H+ O ejection stoichiometry of the cytochrome c oxidase reaction in rat liver miloplasts is close to 4 at level flow when the reduced oxidase is pulsed with O2. Dicyclohexylcarbodiimide (DCCD) up to 30 nmol mg protein fails to influence the rate of electron flow through the mitoplast oxidase, but inhibits H+ ejection. The inhibition of H+ ejection appears to be biphasic; ejection of 2-3 H+ per O is completely inhibited by very low DCCD, whereas inhibition of the remaining H+ ejection requires very much higher concentrations of DCCD. This effect suggests the occurrence of two types of H+ pumps in the native cytochrome oxidase of mitoplasts.

Original languageEnglish (US)
Pages (from-to)335-340
Number of pages6
JournalJournal of Inorganic Biochemistry
Issue number3-4
StatePublished - 1985

ASJC Scopus subject areas

  • Biochemistry
  • Inorganic Chemistry


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