Biomaterial Database

The functional architecture of band 3, the anion transport protein of the red cell membrane. 1984

A Rothstein

Band 3 is an abundant, intrinsic, transmembrane peptide of about 95 000 daltons that mediates anion exchanges across the red blood cell membrane. It is present in the membrane as a dimer with each monomer arranged so that it crosses the bilayer at least five times. Based on proteolytic dissection and the use of covalent probes to "mark" specific sites, it is proposed that the crossing strands form an assembly of alpha-helices, with hydrophobic residues exposed so they are closely associated with the fatty acid side chains of the phospholipids and with hydrophilic residues internalized to form an aqueous core through which transport occurs. Anions cannot freely diffuse through the transport pathway, but are constrained by a "gating" mechanism that requires an electroneutral one-for-one exchange. The process involves the binding of the anions to specific transport sites followed by a local conformational change, such that the sites (with the bound anion) alternate between states that are topologically in and out, with kinetics consistent with a "ping-pong" mechanism. Large organic anions can bind to the transport sites resulting in competitive inhibition. Those such as 4,4'-diisothiocyano-2,2'-stilbene sulfonic acid that can react covalently have been used to mark the transport site in the primary structure of band 3. Sequence data will ultimately allow a much more detailed assessment of the functional architecture of band 3.

UI	MeSH Term	Description	Entries
D008051	Lipid Bilayers	Layers of lipid molecules which are two molecules thick. Bilayer systems are frequently studied as models of biological membranes.	Bilayers, Lipid,Bilayer, Lipid,Lipid Bilayer
D008563	Membrane Lipids	Lipids, predominantly phospholipids, cholesterol and small amounts of glycolipids found in membranes including cellular and intracellular membranes. These lipids may be arranged in bilayers in the membranes with integral proteins between the layers and peripheral proteins attached to the outside. Membrane lipids are required for active transport, several enzymatic activities and membrane formation.	Cell Membrane Lipid,Cell Membrane Lipids,Membrane Lipid,Lipid, Cell Membrane,Lipid, Membrane,Lipids, Cell Membrane,Lipids, Membrane,Membrane Lipid, Cell,Membrane Lipids, Cell
D010446	Peptide Fragments	Partial proteins formed by partial hydrolysis of complete proteins or generated through PROTEIN ENGINEERING techniques.	Peptide Fragment,Fragment, Peptide,Fragments, Peptide
D004910	Erythrocyte Membrane	The semi-permeable outer structure of a red blood cell. It is known as a red cell 'ghost' after HEMOLYSIS.	Erythrocyte Ghost,Red Cell Cytoskeleton,Red Cell Ghost,Erythrocyte Cytoskeleton,Cytoskeleton, Erythrocyte,Cytoskeleton, Red Cell,Erythrocyte Cytoskeletons,Erythrocyte Ghosts,Erythrocyte Membranes,Ghost, Erythrocyte,Ghost, Red Cell,Membrane, Erythrocyte,Red Cell Cytoskeletons,Red Cell Ghosts
D006801	Humans	Members of the species Homo sapiens.	Homo sapiens,Man (Taxonomy),Human,Man, Modern,Modern Man
D000345	Affinity Labels	Analogs of those substrates or compounds which bind naturally at the active sites of proteins, enzymes, antibodies, steroids, or physiological receptors. These analogs form a stable covalent bond at the binding site, thereby acting as inhibitors of the proteins or steroids.	Affinity Labeling Reagents,Labeling Reagents, Affinity,Labels, Affinity,Reagents, Affinity Labeling
D000838	Anions	Negatively charged atoms, radicals or groups of atoms which travel to the anode or positive pole during electrolysis.	Anion
D001457	Anion Exchange Protein 1, Erythrocyte	A major integral transmembrane protein of the ERYTHROCYTE MEMBRANE. It is the anion exchanger responsible for electroneutral transporting in CHLORIDE IONS in exchange of BICARBONATE IONS allowing CO2 uptake and transport from tissues to lungs by the red blood cells. Genetic mutations that result in a loss of the protein function have been associated with type 4 HEREDITARY SPHEROCYTOSIS.	Anion Transport Protein, Erythrocyte,Band 3 Protein,Erythrocyte Anion Transport Protein,Erythrocyte Membrane Band 3 Protein,AE1 Anion Exchanger,AE1 Chloride-Bicarbonate Exchanger,AE1 Cl- HCO3- Exchanger,AE1 Gene Product,Anion Exchanger 1,Antigens, CD233,Band 3 Anion Transport Protein,Band III Protein,CD233 Antigen,CD233 Antigens,Capnophorin,EPB3 Protein,Erythrocyte Anion Exchanger,Erythrocyte Membrane Anion Transport Protein,Erythrocyte Membrane Protein Band 3, Diego Blood Group,Protein Band 3,SLC4A1 Protein,Solute Carrier Family 4 Member 1,Solute Carrier Family 4, Anion Exchanger, Member 1,AE1 Chloride Bicarbonate Exchanger,AE1 Cl HCO3 Exchanger,Anion Exchanger, Erythrocyte,Antigen, CD233,Chloride-Bicarbonate Exchanger, AE1,Exchanger 1, Anion,Protein, EPB3
D012856	4-Acetamido-4'-isothiocyanatostilbene-2,2'-disulfonic Acid	A non-penetrating amino reagent (commonly called SITS) which acts as an inhibitor of anion transport in erythrocytes and other cells.	4-Acetamido-4'-isothiocyanatostilbene-2,2'-disulfonic Acid, Disodium Salt,SITS,SITS Disodium Salt,4 Acetamido 4' isothiocyanatostilbene 2,2' disulfonic Acid,Disodium Salt, SITS
D013654	Taurine	A conditionally essential nutrient, important during mammalian development. It is present in milk but is isolated mostly from ox bile and strongly conjugates bile acids.	Taufon,Tauphon,Taurine Hydrochloride,Taurine Zinc Salt (2:1),Taurine, Monopotassium Salt