Journal of Bioenergetics and Biomembranes

, Volume 45, Issue 1, pp 131–136

Purification and characterization of malate:quinone oxidoreductase from thermophilic Bacillus sp. PS3

Authors

  • Yoshiki Kabashima
    • Department of Bioscience and BioinformaticsKyushu Institute of Technology
    • Department of Chemistry, School of MedicineKyorin University
  • Nobuhito Sone
    • Department of Bioscience and BioinformaticsKyushu Institute of Technology
  • Tomoichirou Kusumoto
    • Department of Bioscience and BioinformaticsKyushu Institute of Technology
    • Department of Bioscience and BioinformaticsKyushu Institute of Technology
Article

DOI: 10.1007/s10863-012-9485-5

Cite this article as:
Kabashima, Y., Sone, N., Kusumoto, T. et al. J Bioenerg Biomembr (2013) 45: 131. doi:10.1007/s10863-012-9485-5

Abstract

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.

Keywords

Malate:quinine oxidoreductase (MQO)Bacillus sp. PS3Membrane-bound dehydrogenase

Supplementary material

10863_2012_9485_MOESM1_ESM.doc (49 kb)
Fig. S1Nucleic acid and amino acid sequences of purified MQO from thermophilic Bacillus sp. PS3. The square shows the N-terminal sequences of the 54-kDa band (Fig. 2, lane 7) revealed using Edman degradation (see Materials and method section). The bold letters show the putative FAD-binding site. (DOC 49 kb)

Copyright information

© Springer Science+Business Media New York 2012