Biomaterial Database

Cytochrome c oxidase of Euglena gracilis: purification, characterization, and identification of mitochondrially synthesized subunits. 1989

U Brönstrup, and W Hachtel

Botanisches Institut der Universität, Bonn, FRG.

Cytochrome c oxidase was purified from mitochondria of Euglena gracilis and separated into 15 different polypeptide subunits by polyacrylamide gel electrophoresis. All 15 subunits copurify through various purification procedures, and the subunit composition of the isolated enzyme is identical to that of the immunoprecipitated one. Therefore, the 15 protein subunits represent integral components of the Euglena oxidase. In an in vitro protein-synthesizing system using isolated mitochondria, polypeptides 1-3 were radioactive labeled in the presence of [35S]methionine. This further identifies these polypeptides with the three largest subunits of cytochrome c oxidase encoded by mitochondrial DNA in other eukaryotic organisms. By subtraction, the other 12 subunits can be assigned to nuclear genes. The isolated Euglena oxidase was highly active with Euglena cytochrome c558 and has monophasic kinetics. Using horse cytochrome c550 as a substrate, activity of the isolated oxidase was rather low. These findings correlate with the oxidase activity of mitochondrial membranes. Again, reactivity was low with cytochrome c550 and 35-fold higher with the Euglena cytochrome c558. The data show that the cytochrome c oxidase of the protist Euglena is different from other eukaryotic cytochrome c oxidases in number and size of subunits, and also with regard to kinetic properties and substrate specificity.

UI	MeSH Term	Description	Entries
D007158	Immunologic Techniques	Techniques used to demonstrate or measure an immune response, and to identify or measure antigens using antibodies.	Antibody Dissociation,Immunologic Technic,Immunologic Technics,Immunologic Technique,Immunological Technics,Immunological Techniques,Technic, Immunologic,Technics, Immunologic,Technique, Immunologic,Techniques, Immunologic,Antibody Dissociations,Dissociation, Antibody,Dissociations, Antibody,Immunological Technic,Immunological Technique,Technic, Immunological,Technics, Immunological,Technique, Immunological,Techniques, Immunological
D007700	Kinetics	The rate dynamics in chemical or physical systems.
D008928	Mitochondria	Semiautonomous, self-reproducing organelles that occur in the cytoplasm of all cells of most, but not all, eukaryotes. Each mitochondrion is surrounded by a double limiting membrane. The inner membrane is highly invaginated, and its projections are called cristae. Mitochondria are the sites of the reactions of oxidative phosphorylation, which result in the formation of ATP. They contain distinctive RIBOSOMES, transfer RNAs (RNA, TRANSFER); AMINO ACYL T RNA SYNTHETASES; and elongation and termination factors. Mitochondria depend upon genes within the nucleus of the cells in which they reside for many essential messenger RNAs (RNA, MESSENGER). Mitochondria are believed to have arisen from aerobic bacteria that established a symbiotic relationship with primitive protoeukaryotes. (King & Stansfield, A Dictionary of Genetics, 4th ed)	Mitochondrial Contraction,Mitochondrion,Contraction, Mitochondrial,Contractions, Mitochondrial,Mitochondrial Contractions
D009492	Neurospora crassa	A species of ascomycetous fungi of the family Sordariaceae, order SORDARIALES, much used in biochemical, genetic, and physiologic studies.	Chrysonilia crassa
D010455	Peptides	Members of the class of compounds composed of AMINO ACIDS joined together by peptide bonds between adjacent amino acids into linear, branched or cyclical structures. OLIGOPEPTIDES are composed of approximately 2-12 amino acids. Polypeptides are composed of approximately 13 or more amino acids. PROTEINS are considered to be larger versions of peptides that can form into complex structures such as ENZYMES and RECEPTORS.	Peptide,Polypeptide,Polypeptides
D011487	Protein Conformation	The characteristic 3-dimensional shape of a protein, including the secondary, supersecondary (motifs), tertiary (domains) and quaternary structure of the peptide chain. PROTEIN STRUCTURE, QUATERNARY describes the conformation assumed by multimeric proteins (aggregates of more than one polypeptide chain).	Conformation, Protein,Conformations, Protein,Protein Conformations
D003576	Electron Transport Complex IV	A multisubunit enzyme complex containing CYTOCHROME A GROUP; CYTOCHROME A3; two copper atoms; and 13 different protein subunits. It is the terminal oxidase complex of the RESPIRATORY CHAIN and collects electrons that are transferred from the reduced CYTOCHROME C GROUP and donates them to molecular OXYGEN, which is then reduced to water. The redox reaction is simultaneously coupled to the transport of PROTONS across the inner mitochondrial membrane.	Cytochrome Oxidase,Cytochrome aa3,Cytochrome-c Oxidase,Cytochrome Oxidase Subunit III,Cytochrome a,a3,Cytochrome c Oxidase Subunit VIa,Cytochrome-c Oxidase (Complex IV),Cytochrome-c Oxidase Subunit III,Cytochrome-c Oxidase Subunit IV,Ferrocytochrome c Oxygen Oxidoreductase,Heme aa3 Cytochrome Oxidase,Pre-CTOX p25,Signal Peptide p25-Subunit IV Cytochrome Oxidase,Subunit III, Cytochrome Oxidase,p25 Presequence Peptide-Cytochrome Oxidase,Cytochrome c Oxidase,Cytochrome c Oxidase Subunit III,Cytochrome c Oxidase Subunit IV,Oxidase, Cytochrome,Oxidase, Cytochrome-c,Signal Peptide p25 Subunit IV Cytochrome Oxidase,p25 Presequence Peptide Cytochrome Oxidase
D004591	Electrophoresis, Polyacrylamide Gel	Electrophoresis in which a polyacrylamide gel is used as the diffusion medium.	Polyacrylamide Gel Electrophoresis,SDS-PAGE,Sodium Dodecyl Sulfate-PAGE,Gel Electrophoresis, Polyacrylamide,SDS PAGE,Sodium Dodecyl Sulfate PAGE,Sodium Dodecyl Sulfate-PAGEs
D005056	Euglena gracilis	A species of fresh-water, flagellated EUKARYOTES in the phylum EUGLENIDA.	Euglena gracili,gracilis, Euglena
D000818	Animals	Unicellular or multicellular, heterotrophic organisms, that have sensation and the power of voluntary movement. Under the older five kingdom paradigm, Animalia was one of the kingdoms. Under the modern three domain model, Animalia represents one of the many groups in the domain EUKARYOTA.	Animal,Metazoa,Animalia