Sweadner K J, Goldin S M
J Biol Chem. 1975 May 25;250(10):4022-4.
Sodium and potassium ion-stimulated adenosine triphosphatase ((Na+ + K+)-ATPase) was partially purified from canine brain gray matter and reconstituted into vesicles of phosphatidylcholine. A proportion of the enzyme molecules was reconstituted into sealed vesicles with the ATP-hydrolyzing site facing the outside of the vesicles. ATP was added to the outside of the vesicles after they had equilibrated with radioactive tracer, and the resulting active transport of Na+ and K+ was followed. Unlike the purified kidney renal medulla enzyme used in an earlier study, the brain enzyme transports both Na+ and K+(Rb+). Vesicles were made in solutions with different proportions of NaCl and KCl, and over the range studied, an average of 1.8 Rb+ ions were transported for every 3 Na+ ions. When ATP is depleted, the transported ions diffuse back to their equilibrium level in the vesicles.
钠钾离子刺激的三磷酸腺苷酶（（Na⁺ + K⁺）-ATP酶）从犬脑灰质中部分纯化，并重组到磷脂酰胆碱囊泡中。一部分酶分子被重组到密封囊泡中，ATP水解位点面向囊泡外部。在囊泡与放射性示踪剂平衡后，将ATP添加到囊泡外部，并跟踪由此产生的Na⁺和K⁺的主动转运。与早期研究中使用的纯化肾髓质酶不同，脑酶能转运Na⁺和K⁺（Rb⁺）。在含有不同比例NaCl和KCl的溶液中制备囊泡，在所研究的范围内，每3个Na⁺离子平均转运1.8个Rb⁺离子。当ATP耗尽时，转运的离子扩散回囊泡中的平衡水平。
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