The molecular size required varies according to the reaction step round the sodium pump cycle

FEBS Letters

Cavieres, J.D.¹ 

[1] Department of Physiology, Leicester University, University Road, Leicester LE1 7RH, England

关键词: Na+;    K+-ATPase;    Na+ pump;    Subunit;    Radiation inactivation;    ATP-binding site;    ATP analog;   

DOI  :  10.1016/0014-5793(87)81147-X

学科分类：生物化学/生物物理

来源: John Wiley & Sons Ltd.

【 摘 要 】

Progress along the path of the sodium pump cycle requires a stepwise recruitment of additional subunits for maximal activity. These results show that whereas a particle the size of the αβ protomer presents Na⁺,K⁺-ATPase activity at 10 μM ATP, an additional subunit, perhaps a second α-chain, is required to obtain the much greater Na⁺,K⁺-ATPase activity resulting from the occupation of low-affinity ATP sites at physiological ATP concentrations. A non-phosphorylating ATP analogue, however, will modestly stimulate the Na⁺,K⁺-ATPase activity acting at an alternative low-affinity site or step on the αβ protomer.

【 授权许可】

Unknown