Hydrolysis by acylphosphatase of erythrocyte membrane Na+, K(+)-ATPase phosphorylated intermediate.
Acylphosphatase, purified from human erythrocytes, actively hydrolyzes the phosphoenzyme intermediate of human red blood cell membrane Na+, K(+)-ATPase. This effect occurred with acylphosphatase amounts (up to 10 units/mg membrane protein) that fall within the physiological range. Acylphosphatase addition to erythrocyte membranes resulted in a significant increase in the rate of Na+, K(+)-dependent ATP hydrolysis. Maximal stimulation, observed with 10 units/mg membrane protein, was of about 80% over basal value. The same acylphosphatase amount enhanced of about 40% the rate of ATP driven Na+ transport into inside out red cell membrane vesicles. Taken together these findings suggest a potential role of acylphosphatase in the control of the activity of erythrocyte membrane Na,K pump.
Nediani
C
C
Dipartimento di Scienze Biochimiche, Università di Firenze, Italy.
Marchetti
E
E
Nassi
P
P
Liguri
G
G
Ramponi
G
G
D017766:Acid Anhydride Hydrolases; D001345:Autoradiography; D001693:Biological Transport, Active; D004910:Erythrocyte Membrane / Q000201:enzymology*; D006868:Hydrolysis; D010744:Phosphoric Monoester Hydrolases / Q000378:metabolism*; D010766:Phosphorylation; D011188:Potassium / Q000378:metabolism; D012964:Sodium / Q000378:metabolism; D000254:Sodium-Potassium-Exchanging ATPase / Q000378:metabolism*; D000097024:Acylphosphatase
D017766:Acid Anhydride Hydrolases; D010744:Phosphoric Monoester Hydrolases; D011188:Potassium; D012964:Sodium; D000254:Sodium-Potassium-Exchanging ATPase; D000097024:Acylphosphatase