Electrogenic Bromosulfalein Transport in Isolated Membrane Vesicles: Implementation in Both Animal and Plant Preparations for the Study of Flavonoid Transporters

Author(s):  
Sabina Passamonti ◽  
Federica Tramer ◽  
Elisa Petrussa ◽  
Enrico Braidot ◽  
Angelo Vianello
1994 ◽  
Vol 68 (6) ◽  
pp. 4009-4016 ◽  
Author(s):  
M C Ruiz ◽  
S R Alonso-Torre ◽  
A Charpilienne ◽  
M Vasseur ◽  
F Michelangeli ◽  
...  

Transport ◽  
1975 ◽  
pp. 117-162 ◽  
Author(s):  
Joy Hochstadt ◽  
Dennis C. Quinlan ◽  
Richard L. Rader ◽  
Chien-Chung Li ◽  
Diana Dowd

1980 ◽  
Vol 58 (6) ◽  
pp. 457-460 ◽  
Author(s):  
M. A. Pickard

Nucleoside entry into isolated membrane vesicles of Micrococcus sodonensis (luteus) was studied using 14C-labelled nucleosides: adenosine, inosine, cytidine, uridine, guanosine, and thymidine. All nucleosides were recovered unmetabolized from the vesicles except adenosine and cytidine which were partly deaminated by membrane-bound enzymes. Vesicle preparations actively transported proline but no energy source was found capable of supporting concentrative nucleoside uptake. The entry of nucleosides into M. sodonensis vesicles was not saturable, nor was there competition between the nucleosides studied for entry. It was concluded that nucleoside entry into M. sodonensis vesicles occurs by passive diffusion.


2010 ◽  
Vol 192 (11) ◽  
pp. 2900-2907 ◽  
Author(s):  
Maarten Groeneveld ◽  
Ruud G. J. Detert Oude Weme ◽  
Ria H. Duurkens ◽  
Dirk Jan Slotboom

ABSTRACT Bacterial secondary transporters of the DctA family mediate ion-coupled uptake of C4-dicarboxylates. Here, we have expressed the DctA homologue from Bacillus subtilis in the Gram-positive bacterium Lactococcus lactis. Transport of dicarboxylates in vitro in isolated membrane vesicles was assayed. We determined the substrate specificity, the type of cotransported ions, the electrogenic nature of transport, and the pH and temperature dependence patterns. DctA was found to catalyze proton-coupled symport of the four C4-dicarboxylates from the Krebs cycle (succinate, fumurate, malate, and oxaloacetate) but not of other mono- and dicarboxylates. Because (i) succinate-proton symport was electrogenic (stimulated by an internal negative membrane potential) and (ii) the divalent anionic form of succinate was recognized by DctA, at least three protons must be cotransported with succinate. The results were interpreted in the light of the crystal structure of the homologous aspartate transporter GltPh from Pyrococcus horikoshii.


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