title: The permeability of bilayer lipid membranes on the incorporation of erythrocyte membrane extracts and the identification of the monosaccharide transport proteins.
abstract: 1. Extracts of the human erythrocyte membrane have been prepared by five different procedures involving Triton X-100 solubilization and gel chromatography. 2. The extracts have been analysed by gel electrophoresis and incorporated asymmetrically into phosphatidylcholine-cholesterol-n-decane planar bilayers. 3. Removal of excess Triton X-100 from membrane extracts or prolonged storage facilities the proteolysis of membrane extracts with the partial or complete breakdown of band 3 polypeptides (notation of Fairbanks, G., Steck, T.L. and Wallach, D.F.H. (1971) Biochemistry 10, 2606--2616) and the appearance of an enhanced zone 4.5 and low molecular weight material. 4. Incorporation of zone 4.5 polypeptides into bilayer lipid membranes increases their permeability to D-glucose at 27 and 5 degrees C. 5. It is suggested that the components of the monosaccharide system are present in band 3 polypeptides but that they can undergo proteolysis with some retention of transport activity.
mesh_terms: D002352:Carrier Proteins / Q000378:metabolism*; D002463:Cell Membrane Permeability; D004910:Erythrocyte Membrane / Q000378:metabolism*; D004912:Erythrocytes / Q000378:metabolism*; D005947:Glucose / Q000378:metabolism*; D006801:Humans; D066298:In Vitro Techniques; D008081:Liposomes; D008565:Membrane Proteins / Q000378:metabolism*
chemical_list: D002352:Carrier Proteins; D008081:Liposomes; D008565:Membrane Proteins; D005947:Glucose