AJP - Cell Physiology, Vol 242, Issue 3 166-C171, Copyright © 1982 by American Physiological Society
Reconstitution of D-glucose transporter from human placental microvillous plasma membranes
J. M. Bissonnette, J. A. Black, K. L. Thornburg, K. M. Acott and P. L. Koch
Proteins from microvillous plasma membrane vesicles of the maternal surface
of human trophoblast were solubilized with octyl beta-D-glucoside. After
incorporation of the soluble protein into phospholipid liposomes D-glucose
uptake exceeded that of L-glucose. The reconstituted system showed that
D-glucose uptake was not sodium dependent and was inhibited by cytochalasin
B. Efflux of D-glucose from the proteoliposomes was retarded by
cytochalasin B. D-Glucose uptake, but not L-glucose, was proportional to
the amount of protein used in the reconstitution procedure. Membrane
protein was also solubilized with octylglucoside from vesicles that had
been extracted previously by dimethylmaleic anhydride. Proteoliposomes
prepared from these latter proteins showed D-glucose uptake threefold
greater than that from octylglucoside solubilization alone, but sodium
dodecyl sulfate polyacrylamide gel electrophoresis of the extracted protein
showed no clear difference between the double extraction procedure and the
pattern obtained with the single detergent.
