Purification and reconstitution of the adipocyte plasma membrane D-glucose transport system.
Rat adipocyte plasma membranes have previously been shown to retain stereospecific transport activity for D-glucose following extraction of extrinsic proteins with dimethylmaleic anhydride (Shanahan, M. F., and Czech, M. P. (1977) J. Biol. Chem. 252, 6554-6561). When these extracted plasma membranes were incubated in 2% sodium cholate and centrifuged, the resultant supernatant contained only one major glycoprotein fraction of 94,000 daltons, as determined by dodecyl sulfate-polyacrylamide gel electrophoresis. This protein fraction was combined with cholate-dispersed, exogenous phospholipids. The detergent was removed by gel filtration and vesicles composed of phospholipid and membrane protein were formed which exhibited preferential, time-dependent uptake of D- versus L-glucose when measured by a rapid filtration method. In addition, D-glucose uptake was inhibited by cytochalasin B, phlorizin, phloretin, and dipyridamole. These results suggest the direct involvement of the 94,000-dalton glycoprotein fraction in fat cell hexose transport.
D000273:Adipose Tissue / Q000378:metabolism*; D000818:Animals; D001693:Biological Transport, Active / Q000187:drug effects; D002462:Cell Membrane / Q000378:metabolism / Q000648:ultrastructure; D005260:Female; D005947:Glucose / Q000378:metabolism*; D007700:Kinetics; D008081:Liposomes / Q000378:metabolism; D008565:Membrane Proteins / Q000502:physiology; D008970:Molecular Weight; D010743:Phospholipids / Q000494:pharmacology; D051381:Rats
D008081:Liposomes; D008565:Membrane Proteins; D010743:Phospholipids; D005947:Glucose