• Research Ins]i[ghts: Nanion’s Transporter Webinar Series 2021
    Register for Session 5 Here

  • SURFE²R N1

    Easy-to-learn all-in-one device, ideal for teaching and university research
  • SURFE²R N1

    Finally label-free functional assays for transporters available
  • SURFE²R N1

    High signal amplification compared to patch-clamp: transport & binding assays
  • SURFE²R N1

    The only instrument on the market for SSM-based electrophysiology
  • SURFE²R N1

    Turn-key system for efficient transporter protein analysis

2011 - G117C MelB, a mutant melibiose permease with a changed conformational equilibrium

Icon N1  SURFE²R-technology (custom-built system) publication in Biochimica et Biophysica Acta (BBA) - Biomembranes (2011)

Ganea C., Meyer-Lipp K., Lemonnier R., Krah A., Leblanc G., Fendler K.

Biochimica et Biophysica Acta (BBA) - Biomembranes (2011) 1808(10):2508-2516


  • Steady-state kinetics of G117C MelB like wild type.
  • Pre steady-state kinetics altered in G117C MelB.
  • Initial configuration of G117C MelB differs from wild type.
  • Rapid dynamic equilibrium of substrate free transporter.


Replacement of the glycine at position 117 by a cysteine in the melibiose permease creates an interesting phenotype: while the mutant transporter shows still transport activity comparable to the wild type its pre steady-state kinetic properties are drastically altered. The transient charge displacements after substrate concentration jumps are strongly reduced and the fluorescence changes disappear. Together with its maintained transport activity this indicates that substrate translocation in G117C melibiose permease is not impaired but that the initial conformation of the mutant transporter differs from that of the wild type permease. A kinetic model for the G117C melibiose permease based on a rapid dynamic equilibrium of the substrate free transporter is proposed. Implications of the kinetic model for the transport mechanism of the wild type permease are discussed.

Download here

Back to Overview

We use cookies on our website. Some of them are essential for the operation of the site, while others help us to improve this site and the user experience (tracking cookies). You can decide for yourself whether you want to allow cookies or not. Please note that if you reject them, you may not be able to use all the functionalities of the site.