Intracellular potassium promotes antibody binding to an antigen associated with the Na/K pump of sheep erythrocytes.
Anti-Lp antibody is known to bind to sheep red cells and to stimulate the Na/K pump. The antibody acts by reducing the affinity of the pumps for intracellular K as a noncompetitive inhibitor. We now show that intracellular K enhances the extent of anti-Lp binding to the pump-associated antigens. Cells made with approximately 60 mmol/1 K bound approximately 60% more anti-Lp than cells with O K; binding was assayed by measuring the extent of stimulation of the pump-mediated K influx.
D000818:Animals; D000915:Antibody Affinity; D000937:Antigen-Antibody Reactions; D003600:Cytosol / Q000502:physiology; D004912:Erythrocytes / Q000201:enzymology*; D011188:Potassium / Q000502:physiology*; D011487:Protein Conformation; D012756:Sheep; D012964:Sodium / Q000097:blood; D000254:Sodium-Potassium-Exchanging ATPase / Q000097:blood* / Q000276:immunology; D013329:Structure-Activity Relationship
D012964:Sodium; D000254:Sodium-Potassium-Exchanging ATPase; D011188:Potassium