Electrical properties and glucose permeability of bilayer lipid membranes on incorporation of erythrocyte membrane extracts.
1. Extracts of the human erythrocyte membrane have been prepared by solubilization with Triton X-100 and analysed by electrophoresis and gel filtration techniques. 2. The extracts have been incorporated asymmetrically into lecithincholesterol-n-decane planar bilayers. 3. The electrical characteristics and glucose permeabilities of the bilayers have been measured. 4. The extracts increased the electrical conductance of the bilayers and also markedly enhanced the D-glucose permeability but not the L-glucose permeability. 5. The enhanced D-glucose permeability was inhibited by monosaccharide transport inhibitors. 6. The results support the claim that a monosachharide facititated diffusion system has been set-up in vitro which has many of the characteristics of the transport system in the human erythrocyte membrane. 7. The data indicates that the trans membrane polypeptides of band 3 of the electrophoretogram of the erythrocyte membrane proteins (notation of Fairbanks, G., Steck, T.L. and Wallach, D.F.H. (1971) Biochemistry 10, 2606-2616) are implicated in D-glucose transport, although the possibility that relatively minor component of the membrane could be responsible for glucose transport cannot be eliminated.
D002463:Cell Membrane Permeability; D004553:Electric Conductivity; D004910:Erythrocyte Membrane / Q000502:physiology*; D004912:Erythrocytes / Q000502:physiology*; D005947:Glucose / Q000378:metabolism*; D006801:Humans; D008565:Membrane Proteins / Q000032:analysis / Q000502:physiology*; D008567:Membranes, Artificial; D008970:Molecular Weight; D013237:Stereoisomerism
D008565:Membrane Proteins; D008567:Membranes, Artificial; D005947:Glucose