Cytochalasin B-sensitive, sodium ion-dependent glucose transport in intestinal microvillous membrane.
It was found that sodium ion-dependent glucose uptake by microvillous membrane (MVM) vesicles was partially inhibited by cytochalasin B with a half-maximum inhibition at ca. 10 microM. The MVM was photolabeled with [3]cytochalasin B. The Kd value and the maximum number of binding sites for cytochalasin B were ca. 8 microM and 70 pmol/mg protein, respectively. SDS-PAGE of the photolabeled MVM revealed 2 binding components. One was 86 K in Mr and the other 42 K. The binding of cytochalasin B to the 86 K component was affected neither by cytochalasin E nor by the presence of 0.5 M NaCl, but was depressed in the presence of 2-deoxy-D-glucose or phlorizin, which had no effect on the labeling of the 42 K component. These and other data suggested that the 86 K component might be responsible for a cytochalasin B-sensitive glucose transport in intestinal epithelial MVM.
Uezato
T
T
Department of Biochemistry, Hamamatsu University School of Medicine, Handa-cho, Japan.
Fujita
M
M
D000818:Animals; D002241:Carbohydrates / Q000494:pharmacology; D003571:Cytochalasin B / Q000378:metabolism / Q000494:pharmacology*; D007421:Intestine, Small / Q000378:metabolism*; D051379:Mice; D008815:Mice, Inbred Strains; D008871:Microvilli / Q000378:metabolism*; D008970:Molecular Weight; D009004:Monosaccharide Transport Proteins / Q000032:analysis*; D014316:Tritium
D002241:Carbohydrates; D009004:Monosaccharide Transport Proteins; D014316:Tritium; D003571:Cytochalasin B