DEMONSTRATION OF 2 BINDING-SITES FOR ADP ON THE ISOLATED BETA-SUBUNIT OF THE RHODOSPIRILLUM-RUBRUM R1F0F1-ATP SYNTHASE

作     者：KHANANSHVILI, D GROMETELHANAN, Z 

作者机构：WEIZMANN INST SCIDEPT BIOCHEMIL-76100 REHOVOTISRAEL 

出 版 物：《FEBS LETTERS》 (FEBS Lett.)

年 卷 期：1984年第178卷第1期

页      面：10-14页

核心收录：

学科分类：0710[理学-生物学] 071010[理学-生物化学与分子生物学] 07[理学] 

基　　金：Minerva Foundation Munich/FRG 

主　　题：Rhodospirillum rubrum F 0 F 1 -ATPsynthase β-Subunit ADP-binding site MgCl 2 dependence Binding affinity 

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 MgCl 2 and is unaffected by it. The second is a low affinity binding site ( K d = 80 μM) that is absolutely dependent on MgCl 2 . For stable binding of ADP to this site, MgCl 2 must be present not only during the binding step but also during the elution-centrifugation step used to separate the β-subunit bound [ 3 H]ADP from the free ligand. When MgCl 2 is removed together with the free ligand [ 3 H]ADP dissociates very rapidly from this second binding site.