Native states of adenylate kinase are two active sub‐ensembles

FEBS Letters

Pan, Xianming¹  Han, Yang¹  Li, Xia¹ 

[1] National Laboratory of Biomacromolecules, Institute of Biophysics, Academia Sinica, 15 Datun Road, Beijing 100101, PR China

关键词: Adenylate kinase;    AP5A;    Multiple native conformers;    Ensemble;    Active energy;    Kinetic control;    Thermodynamic control;    Protein folding;    AK;    rabbit muscle adenylate kinase;    ANS;    8-anilino-1-naphthalenesulfonic acid;   

DOI  :  10.1016/S0014-5793(02)03291-X

学科分类：生物化学/生物物理

来源: John Wiley & Sons Ltd.

【 摘 要 】

There are two kinds of conformational forms of adenylate kinase (AK) in equilibrium in solution with different ANS-binding properties. Furthermore, the nature of AP₅A inhibition suggests also that the native forms of AK for binding with different substrates pre-exist in the absence of substrates. In the present study, a kinetics approach was used to explore the native forms distinguished by ANS-binding properties and by the nature of AP₅A inhibition. The results revealed that the native forms distinguished by ANS probe are two conformational sub-ensembles. Both sub-ensembles are active and consist of a series of forms, which pre-exist in solution and can bind with different substrates. The K _m values of N₁ for AMP, ADP and MgATP are larger than that of N₂, indicating that the N₂ sub-ensemble is more specific for binding substrates. This is consistent with the previous observation that the activity of N₂ is about 1.8-fold of that of N₁.

【 授权许可】

Unknown