Na+-K+ATP PUMP Low-affinity High-affinity Na'-binding sites K+-binding site E1 > E1 个 ATP site High-affinity Low-affinity Na'-binding K+-binding ATP ADP E1→E2 site sites Binding of ATP, conformational phosphorylation change,outward Binding of 3 Na'ions of aspartate transport of Na+ E2 E2 Q P Dissociation Hydrolysis E2>E1 Dissociation of Na+, of aspartyl conformational of K+ions binding of K* phosphate change,inward transport of K+ Na+-K+ATP PUMP