Functional Reconstitution into Liposomes of Purified Human RhCG Ammonia Channel

Functional Reconstitution into Liposomes of Purified Human RhCG Ammonia Channel

BACKGROUND Rh glycoproteins (RhAG, RhBG, RhCG) are members of the Amt/Mep/Rh family which facilitate movement of ammonium across plasma membranes. Changes in ammonium transport activity following expression of Rh glycoproteins have been described in different heterologous systems such as yeasts, oocytes and eukaryotic cell lines. However, in these complex systems, a potential contribution of en...

K+-conducting ion channel of the chloroplast inner envelope: functional reconstitution into liposomes.

Potassium flux between the chloroplast stroma and cytoplasm is known to be indirectly linked to H+ countertransport and, hence, stromal pH and photosynthetic capacity. The specific molecular mechanism that facilitates K+ flux across the chloroplast envelope is not known and has been a source of controversy for well over a decade. The objective of this study was to elucidate the nature of this e...

Reconstitution of purified bacterial preprotein translocase in liposomes.

Unidirectional reconstitution into detergent-destabilized liposomes of the purified lactose transport system of Streptococcus thermophilus.

The lactose transport protein (LacS) of Streptococcus thermophilus was amplified to levels as high as 8 and 30% of total membrane protein in Escherichia coli and S. thermophilus, respectively. In both organisms the protein was functional and the expression levels were highest with the streptococcal lacS promoter. Also a LacS deletion mutant, lacking the carboxyl-terminal regulatory domain, coul...

Reconstitution of flippase activity into liposomes.

Phospholipids are asymmetrically distributed in the plasma membrane of eucaryotic cells, the aminophospholipids being mostly on the cytosolic leaflet, whilst the choline containing phospholipids (phosphatidylcholine and sphingomyelin) are predominantly exposed on the outer leaflet [1]. There is strong evidence in support of the role of specific proteins (" flippases ") that are involved in the ...