Retention of insulin-stimulated D-glucose transport activity by adipocyte plasma membranes following extraction of extrinsic proteins.
Plasma membrane vesicles prepared from adipocytes incubated with insulin exhibited accelerated D-glucose transport activity characteristic to insulin action on intact fat cells. Both control and insulin-stimulated D-glucose transport activities were inhibited by cytochalasin B and thiol reagents. Extraction of plasma membranes with dimethylmaleic anhydride eluted 80% of the protein from plasma membrane vesicles. The two major glycoprotein bands (94,000 and 78,000 daltons) and small amounts of a 56,000-dalton band were retained in dodecyl sulfate gels of the extracted membranes. Both control and insulin-activated D-glucose transport activities were retained by plasma membrane vesicles extracted with dimethylmaleic anhydride. Cytochalasin B binding activity was also retained by extracted membrane vesicles and D-glucose uptake into extracted vesicles derived from untreated or insulin-treated fat cells was inhibited by cytochalasin B. These results suggest that the modification of the adipocyte hexose transport system elicited by insulin action is not altered by a major purification step which involves quantitative extraction of extrinsic membrane proteins.
D000273:Adipose Tissue / Q000378:metabolism*; D000818:Animals; D001693:Biological Transport, Active / Q000187:drug effects; D002352:Carrier Proteins / Q000378:metabolism; D002462:Cell Membrane / Q000187:drug effects / Q000378:metabolism / Q000648:ultrastructure; D002474:Cell-Free System; D003571:Cytochalasin B / Q000378:metabolism; D005260:Female; D005947:Glucose / Q000378:metabolism*; D007328:Insulin / Q000494:pharmacology*; D008299:Maleic Anhydrides / Q000494:pharmacology; D008565:Membrane Proteins / Q000378:metabolism*; D051381:Rats
D002352:Carrier Proteins; D007328:Insulin; D008299:Maleic Anhydrides; D008565:Membrane Proteins; D003571:Cytochalasin B; D005947:Glucose