Fractionation of rat liver plasma-membrane regions by two-phase partitioning.
Rat liver plasma membranes, enriched in blood-sinusoidal or bile-canalicular regions by differential and sucrose-gradient centrifugation, were further purified by partitioning in an aqueous polymer two-phase system. This method separates membranes according to differences in surface properties rather than size and density. A several-fold increase in the ratio of leucine aminopeptidase (a bile-canalicular marker) and 5'-nucleotidase to asialo-orosomucoid binding (a blood-sinusoidal marker) was obtained in one fraction, whereas another fraction gave a 2-3-fold increase in ratio of blood-sinusoidal to bile-canalicular markers. Furthermore, the markers for both regions of the plasma membrane, as well as markers for Golgi membranes and lysosomes, showed a heterogeneous behaviour on counter-current distribution.
D000818:Animals; D002458:Cell Fractionation / Q000379:methods*; D002462:Cell Membrane / Q000201:enzymology; D003377:Countercurrent Distribution; D008099:Liver / Q000201:enzymology / Q000648:ultrastructure*; D008297:Male; D011108:Polymers; D011189:Potassium Chloride; D051381:Rats; D011919:Rats, Inbred Strains
D011108:Polymers; D011189:Potassium Chloride