Demonstration of two binding sites for ADP on the isolated β‐subunit of the Rhodospirillum rubrum R1F0F1‐ATP synthase

FEBS Letters

Khananshvili, Daniel¹  Gromet-Elhanan, Zippora¹ 

[1] Department of Biochemistry, The Weizmann Institute of Science, Rehovot 76100, Israel

关键词: Rhodospirillum rubrum F0F1-ATPsynthase β-Subunit ADP-binding site MgCl2 dependence Binding affinity;   

DOI  :  10.1016/0014-5793(84)81229-6

学科分类：生物化学/生物物理

来源: John Wiley & Sons Ltd.

【 摘 要 】

Two ADP binding sites have been demonstrated on the reconstitutively active β-subunit, that was removed from the Rhodospirillum rubrum membrane-bound ATP synthase. One is a high affinity site (K _d = 0.7 μM) that does not require MgCl₂ and is unaffected by it. The second is a low affinity binding site (K _d = 80 μM) that is absolutely dependent on MgCl₂. For stable binding of ADP to this site, MgCl₂ must be present not only during the binding step but also during the elution-centrifugation step used to separate the β-subunit bound [³H]ADP from the free ligand. When MgCl₂ is removed together with the free ligand [³H]ADP dissociates very rapidly from this second binding site.

【 授权许可】

Unknown