title: Demonstration of two isoforms of subunit VIIa of cytochrome c oxidase from human skeletal muscle. Implications for mitochondrial myopathies.
abstract: Two different isoforms of subunit VIIa have been found in cytochrome c oxidase isolated from human skeletal muscle. The first 22 residues of the N-terminal amino acid sequences showed 5 differences. Our results provide the first conclusive evidence for the existence of cytochrome c oxidase isoenzymes in man. Since the two cytochrome c oxidase isoforms were both present in skeletal muscle tissue, though not necessarily in the same cell type, this suggests that human cytochrome c oxidase isoforms are not strictly tissue-specific. These findings may have important implications for the elucidation of genetic diseases in man in which a deficiency of cytochrome c oxidase is restricted to certain tissues.
authors.affiliation: Laboratory of Microbiology and Microbial Genetics, University of Gent, Belgium.
authors.forename: J J
authors.initials: JJ
authors.lastname: Van Beeumen
authors.forename: A B
authors.initials: AB
authors.lastname: Van Kuilenburg
authors.forename: S
authors.initials: S
authors.lastname: Van Bun
authors.forename: C
authors.initials: C
authors.lastname: Van den Bogert
authors.forename: J M
authors.initials: JM
authors.lastname: Tager
authors.forename: A O
authors.initials: AO
authors.lastname: Muijsers
mesh_terms: D000595:Amino Acid Sequence; D002851:Chromatography, High Pressure Liquid; D003576:Electron Transport Complex IV / Q000302:isolation & purification*; D004591:Electrophoresis, Polyacrylamide Gel; D006801:Humans; D007527:Isoenzymes / Q000302:isolation & purification*; D008969:Molecular Sequence Data; D009132:Muscles / Q000201:enzymology*; D009135:Muscular Diseases / Q000201:enzymology
chemical_list: D007527:Isoenzymes; D003576:Electron Transport Complex IV