Construction and characterization of heterodimeric soluble quinoprotein glucose dehydrogenase

J Biochem Biophys Methods. 2004 Nov 30;61(3):331-8. doi: 10.1016/j.jbbm.2004.06.009.

Abstract

In order to study in greater detail the subunit interaction of the homodimeric soluble quinoprotein glucose dehydrogenase (PQQGDH-B), we developed an effective method of creating heterodimeric PQQGDH-B. Two different homodimers are combined, one of which has a polyarginine tail (Arg-tail), and subjected to a protein dissociation/redimerization procedure. Separation of the mixture by cation exchange chromatography results in three peaks showing GDH activity, eluting at 133, 231 and 273 mM NaCl concentration. These peaks were determined to correspond to the Arg-tailless homodimer, heterodimer, and Arg-tailed homodimer, respectively. To test this approach, we constructed and characterized heterodimeric PQQGDH-B composed of native (wild-type) and inactive mutant (His168Gln) subunits. The heterodimeric wild-type-His168Gln showed slightly decreased GDH activity and almost identical substrate specificity profile to the wild-type enzyme. Moreover, the Hill coefficient of the heterodimer was calculated as 1.13, indicating positive cooperativity.

Publication types

  • Comparative Study
  • Evaluation Study

MeSH terms

  • Amino Acid Substitution
  • Dimerization
  • Enzyme Activation
  • Glucose Dehydrogenases / analysis*
  • Glucose Dehydrogenases / chemistry*
  • Multiprotein Complexes / analysis
  • Multiprotein Complexes / chemistry
  • Mutagenesis, Site-Directed
  • Recombinant Proteins / analysis
  • Recombinant Proteins / chemistry
  • Solubility
  • Structure-Activity Relationship

Substances

  • Multiprotein Complexes
  • Recombinant Proteins
  • Glucose Dehydrogenases
  • glucose dehydrogenase (pyrroloquinoline-quinone)