Molecular dissection of water and glycerol permeability of the aquaglyceroporin from Plasmodium falciparum by mutational analysis.

ABSTRACT: The selectivity of aquaporins for water and solutes is determined by pore diameter. Paradoxically, the wider pores of glycerol facilitators restrict water passage by an unknown mechanism. Earlier we characterized an aquaglyceroporin from Plasmodium falciparum with high permeability for both glycerol and water. We use point mutations to demonstrate that amino acids directly lining the pore are not responsible for the excellent water permeability of the Plasmodium aquaglyceroporin but affect permeability of pentitols. Within a conserved WET triad in the extracellular C-loop we identified a Plasmodium aquaglyceroporin-specific glutamate (E125) located in proximity to a conserved arginine (R196) at the pore mouth. Mutation of E125 to serine largely abolished water permeability. Concomitantly,

SUBMITTER: Beitz E 

PROVIDER: S-EPMC337022 | biostudies-literature | 2004 Feb

REPOSITORIES: biostudies-literature