Purification of the Chlorella HUP1 hexose-proton symporter to homogeneity and its reconstitution in vitro

Allbwn ymchwil: Cyfraniad at gyfnodolynErthygladolygiad gan gymheiriaid

Fersiynau electronig

Dangosydd eitem ddigidol (DOI)

  • T Caspari
    Lehstuhl für Zellbiologische und Pflanzenphysiologie, Universität Regensburg, Regensburg
  • Ingrid Robl
    Lehstuhl für Zellbiologische und Pflanzenphysiologie, Universität Regensburg, Regensburg
  • J Stolz
  • Widmar Tanner
    Lehstuhl für Zellbiologische und Pflanzenphysiologie, Universität Regensburg, Regensburg

A prokaryotic biotin acceptor domain was fused to the carboxy terminal end of the Chlorella hexose-proton symporter. The plant symporter is biotinylated in vivo when expressed in Schizosaccharomyces pombe. The extended biotinylated transport protein is fully active, catalyzes accumulation of D-glucose analogs and restores growth of a glucose-uptake-deficient yeast strain. Crude membranes were solubilized with octyl-beta-D-glucoside in the presence of Escherichia coli L-alpha-phosphatidylethanolamine. Biotinylated symporter was purified to homogeneity by biotinavidin affinity chromatography. The symporter protein was reconstituted together with cytochrome-c oxidase prepared from beef heart mitochondria into proteo-liposomes. Cytochrome-c oxidase is a redox-driven H(+)-pump generating a proton motive force (inside negative and alkaline) while transferring electrons from cytochrome-c to oxygen; this energy is used by the symporter to accumulate D-glucose at least 30-fold. In the absence of the driving force the transport protein facilitates diffusion of D-glucose until the concentration equilibrium is reached. It was shown that maximal transport activity depends highly on the amount of co-reconstituted cytochrome-c oxidase and that the symporter possesses 10% of its in vivo turnover number under optimized in vitro transport conditions.

Allweddeiriau

Iaith wreiddiolSaesneg
Tudalennau (o-i)1045-53
Nifer y tudalennau9
CyfnodolynPlant Journal
Cyfrol10
Rhif y cyfnodolyn6
Dynodwyr Gwrthrych Digidol (DOIs)
StatwsCyhoeddwyd - Rhag 1996
Gweld graff cysylltiadau