title: Structural and functional organization of Complex I in the mitochondrial respiratory chain.
abstract: Metabolic flux control analysis of NADH oxidation in bovine heart submitochondrial particles revealed high flux control coefficients for both Complex I and Complex III, suggesting that the two enzymes are functionally associated as a single enzyme, with channelling of the common substrate, Coenzyme Q. This is in contrast with the more accepted view of a mobile diffusable Coenzyme Q pool between these enzymes. Dilution with phospholipids of a mitochondrial fraction enriched in Complexes I and III, with consequent increased theoretical distance between complexes, determines adherence to pool behavior for Coenzyme Q, but only at dilution higher than 1:5 (protein:phospholipids), whereas, at lower phospholipid content, the turnover of NADH cytochrome c reductase is higher than expected by the pool equation.
authors.affiliation: Universtiy of Bologna, Bologna, Italy.
authors.forename: Cristina
authors.initials: C
authors.lastname: Bianchi
authors.forename: Romana
authors.initials: R
authors.lastname: Fato
authors.forename: Maria Luisa
authors.initials: ML
authors.lastname: Genova
authors.forename: Giovanna
authors.initials: G
authors.lastname: Parenti Castelli
authors.forename: Giorgio
authors.initials: G
authors.lastname: Lenaz
mesh_terms: D000818:Animals; D002417:Cattle; D002462:Cell Membrane / Q000737:chemistry / Q000201:enzymology; D004579:Electron Transport; D042967:Electron Transport Complex I / Q000737:chemistry* / Q000502:physiology*; D014450:Electron Transport Complex III / Q000378:metabolism; D008929:Mitochondria, Heart / Q000201:enzymology* / Q000648:ultrastructure; D009243:NAD / Q000378:metabolism; D010084:Oxidation-Reduction; D010743:Phospholipids / Q000032:analysis; D013367:Submitochondrial Particles / Q000201:enzymology; D014451:Ubiquinone / Q000378:metabolism
chemical_list: D010743:Phospholipids; D009243:NAD; D014451:Ubiquinone; D042967:Electron Transport Complex I; D014450:Electron Transport Complex III