Purification and characterization of malate:quinone oxidoreductase from thermophilic Bacillus sp. PS3
Autor: | Junshi Sakamoto, Nobuhito Sone, Yoshiki Kabashima, Tomoichirou Kusumoto |
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Rok vydání: | 2012 |
Předmět: |
chemistry.chemical_classification
Oxidase test biology Molecular mass Cytochrome Physiology Thermophile Geobacillus Membrane Proteins Bacillus Vitamin K 2 Cell Biology biology.organism_classification Kinetics Enzyme Bacterial Proteins Biochemistry chemistry biology.protein Bioorganic chemistry Oxidoreductases Oxidation-Reduction Phylogeny Bacteria |
Zdroj: | Journal of Bioenergetics and Biomembranes. 45:131-136 |
ISSN: | 1573-6881 0145-479X |
Popis: | Several bacteria possess membrane-bound dehydrogenases other than cytosolic dehydrogenases in their respiratory chains. In many cases, the membrane-bound malate:quinone oxidoreductases (MQOs) are essential for growth. However, these MQOs are absent in mammalian mitochondria, and therefore may be a potential drug target for pathogenic bacteria. To characterize the kinetic properties of MQOs, we purified MQO from Bacillus sp. PS3, which is a gram-positive and thermophilic bacterium, and cloned the gene encoding MQO based on the obtained partial N-terminus sequence. Purified MQOs showed a molecular mass of ~90 kDa, which was estimated using gel filtration, and it consists of two subunits with a molecular mass of ~50 kDa. Phylogenetic analysis showed a high similarity to the MQO of the Geobacillus group rather than the Bacillus group. Additionally, the purified enzyme was thermostable and it retained menaquinol reduction activity at high temperatures. Although it is difficult to conduct experiments using menaquinol because of its instability, we were able to measure the oxidase activity of cytochrome bd-type quinol oxidase by using menaquinol-1 by coupling this molecule with the menaquinol reduction reaction using purified MQOs. |
Databáze: | OpenAIRE |
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