Retention of insulin-stimulated D-glucose transport activity by adipocyte plasma membranes following extraction of extrinsic proteins
✍ Scribed by Pillion, Dennis J. ;Shanahan, Michael F. ;Czech, Michael P.
- Publisher
- Wiley (John Wiley & Sons)
- Year
- 1978
- Tongue
- English
- Weight
- 570 KB
- Volume
- 8
- Category
- Article
- ISSN
- 0091-7419
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✦ Synopsis
Plasma membrane vesicles prepared from adipocytes incubated with insulin exhibited accelerated D-glucose transport activity characteristic of insulin action o n 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.