Guanine nucleotides and magnesium dependence of the association states of the subunits of transducin

FEBS Letters

Chabre, Marc¹  Bigay, Joëlle¹  Déterre, Philippe¹  Pfister, Claude¹ 

[1] Laboratoire de Biologie Moléculaire et Cellulaire (ER 199 CNRS), DRF-CEN-Grenoble, BP 85X F-38041 Grenoble, France

关键词: Transducin;    GTP-binding protein;    Magnesium;    Retinal rod;    T;    transducin;    ROS;    rod outer segments;    GTPγS;    guanosine 5'-O-(3-thiotriphosphate);    FPLC;    fast protein liquid chromatography;   

DOI  :  10.1016/0014-5793(84)80606-7

学科分类：生物化学/生物物理

来源: John Wiley & Sons Ltd.

【 摘 要 】

When GTP_γS is bound to transducin (T), the two subunits T_α·GTP_γS and T_βγ dissociate, independently of the ionic environment. When GDP is bound, these subunits are associated as a monomeric T_α·GDP-T_βγ complex of 75 kDa when the ionic environment is comparable to that of the cytoplasm, but they dissociate in the presence of 10–100 mM Mg²⁺ or Ca²⁺ Using this property, the subunits could be separated and purified by a rapid one-step procedure on an ion-exchange column (FPLC), and their molecular masses were verified by neutron small angle scattering. The physiological relevances of the dissociating effect of Mg²⁺ are discussed.

【 授权许可】

Unknown