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Structural and functional organization of Complex I in the mitochondrial respiratory chain
Author(s) -
Bianchi Cristina,
Fato Romana,
Genova Maria Luisa,
Castelli Giovanna Parenti,
Lenaz Giorgio
Publication year - 2003
Publication title -
biofactors
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 1.204
H-Index - 94
eISSN - 1872-8081
pISSN - 0951-6433
DOI - 10.1002/biof.5520180202
Subject(s) - mitochondrial respiratory chain , respiratory chain , chain (unit) , respiratory system , functional organization , neuroscience , computational biology , mitochondrion , chemistry , biology , microbiology and biotechnology , physics , anatomy , astronomy
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.