The Red Cell Membrane: A Model for Solute Transport

'1. Introduction.- Why Red Cells?.- 1. Introduction.- 2. Transport Systems in Mature Red Cells.- 2.1. Transport of Inorganic Ions.- 2.2. Transport of Organic Molecules.- 2.3. Comparative Aspects.- 2.4. Conclusion.- 3. Advantages of Red Cells.- 4. Conclusion.- References.- Need and Applications of Integrated Red Cell Models.- 1. Introduction.- 2. General Considerations.- 2.1. Purpose and Requirements of an Integrated Red-Cell Model.- 2.2. Components of an Integrated Red-Cell Model.- 2.3. The Computation Strategy.- 3. Examples.- 3.1. Computing a Reference Steady State for a Reticulocyte.- 3.2. Experimental Test of Predictions of the Behavior of K-Permeabilized Red Cells.- References.- 2. Biochemistry and Biophysics.- Molecular Structure of the Na,K,-ATPase.- 1. Introduction.- 2. The Subunits and Their Function.- 2.1. ?-Subunit.- 2.2. ?-Subunit.- 2.3. ?-Subunit.- 3. The Structure of the ?-Subunit.- 3.1. Molecular Weight.- 3.2. Isoforms.- 3.3. ?-Subunit in the Red Blood Cell.- 3.4. Primary Structure.- 3.5. Secondary and Tertiary Structure.- 4. The Structure of the ?-Subunit.- 4.1. Molecular Weight.- 4.2. Primary Structure.- 4.3. Secondary and Tertiary Structure.- 5. Stoichiometry.- 5.1. Mass Ratios.- 5.2. Chemical Cross-Linking Studies.- 5.3. Functional Unit.- 6. Structure-Function Relationships.- 6.1. Amino-Terminal Domain.- 6.2. Conformational Transitions and Ion Binding.- 6.3. ATP Binding and Hydrolysis.- 6.4. Binding of Cardiac Glycosides.- 7. Summary.- References.- Enzymatic and Functional Aspects of Na+/K+ Transport.- 1. Introduction.- 2. Modes of Pump Behavior and Their Enzymic Correlates.- 2.1. Na/Na Exchange, K/K Exchange, Uncoupled Na+ Efflux and Uncoupled K+ Efflux.- 2.2. Affinities of Cations and the Role of Protons.- 3. Are There Characteristics of the Na,K-ATPase Unique to Red Cells?.- 3.1. Effects of Temperature.- 3.2. Interactions with Ouabain.- 3.3. Intracellular Ca2+.- 3.4. Membrane-Bound Glycolytic Enzymes and Their Interactions with Na,K-ATPase via Compartmentalized ATP.- 4. Functional Variants of the Na,K-ATPase: Sodium Pump Behavior in Genetically Dimorphic Sheep Red Blood Cells.- 5. Conclusion.- References.- The (Ca2+ + Mg2+)-ATPase: Purification and Reconstitution.- 1. Introduction.- 2. Purification of (Ca2+ + Mg2+)-ATPase.- 2.1. Early Attempts.- 2.2. Calmodulin-Affinity Chromatography.- 3. Kinetic Properties of the Purified Enzyme.- 3.1. Requirement for Phospholipids.- 3.2. Calmodulin-Insensitive Forms.- 4. Reconstitution of (Ca2+ + Mg2+)-ATPase.- 4.1. Early Attempts.- 4.2. Principle of the Methods.- 4.3. Characterization of the Proteoliposomes.- 4.4. Properties of the Reconstituted Enzyme.- 4.5. Mechanism of Ca2+ Transport.- 5. Summary and Conclusions.- References.- Catalytic Mechanisms of the Ca-Pump ATPase.- 1. Introduction.- 2. The Main Properties of the Transport of Ca2+ and the Hydrolysis of ATP by the Ca-Pump ATPase.- 2.1. Transport of Ca2+.- 2.2. Hydrolysis of ATP.- 2.3. Elementary Steps of ATP Hydrolysis.- 2.4. Phosphatase Activity of the Ca-Pump ATPase.- 2.5. Activators of the Ca-Pump ATPase.- 2.6. Inhibitors of the Ca-Pump ATPase.- 3. Summary and Conclusions.- References.- Regulation of the Plasma Membrane Ca2+-Pump.- 1. Introduction.- 2. Does the RBC Need a Regulated Ca2+-Pump?.- 3. ATP as a Regulator of the Ca2+ -Pump.- 4. Calmodulin as a Regulator of the Ca2+-Pump.- 5. Anti-CaM Drugs as Modifiers of the Ca2+-Pump.- 6. Lipids as Regulators of the Ca2+-Pump.- 7. Mechanically Induced Ca2+ Permeation as a Regulator of the Ca2+-Pump.- 8. Diseases as Modifiers of the Ca2+-Pump.- 9. RBCs as Models for Ca2+ Transport.- 10. Summary.- References.- The Anion Transport Protein: Structure and Function.- 1. Introduction.- 2. Structural Domains.- 2.1. Cytoplasmic Domain.- 2.2. Membrane Domain.- 3. The Anion Transport Pathway.- 3.1. Minimum Structure Required for Transport.- 3.2. Extracellular Aspect: The Stilb