Effect of transmembrane Ca2+ gradient on Gs function

FEBS Letters

Yang, Fu-yu¹  Bai, Yan-hong¹  Huang, You-guo¹  Fan, Gao-feng¹ 

[1]National Laboratory of Biomacromolecules, Institute of Biophysics, Chinese Academy of Sciences, Beijing 100101, China

关键词: Transmembrane Ca2+ gradient;    Stimulatory GTP-binding protein;    Gs;    Adenylate cyclase;    Lipid fluidity;    Gs;    stimulatory GTP-binding protein;    GTPγS;    guanosine 5′-O-(3-thiotriphosphate);    DPH;    diphenylhexatriene;    [Ca2+];    Ca2+ concentration;    ATP;    adenosine triphosphate;    GTP;    guanosine triphosphate;    DTT;    dithiothreitol;    cAMP;    cyclic adenosine monophosphate;    SDS;    sodium dodecyl sulfate;    kDa;    kilodalton;    Tris;    N-tris(hydroxymethyl)aminomethane;   

DOI  :  10.1016/0014-5793(94)01307-M

学科分类：生物化学/生物物理

来源: John Wiley & Sons Ltd.

【 摘 要 】

G_s and adenylate cyclase from bovine brain cortices were co-reconstituted into asolectin liposomes with or without 1000-fold transmembrane Ca²⁺ gradient. Obtained results showed that G_s activities of both binding GTPγS and stimulating adenylate cyclase were the highest in proteoliposomes, with a transmembrane Ca²⁺ gradient similar to the physiological situation and the lowest while the transmembrane Ca²⁺ gradient was in the inverse direction. Such a difference could be diminished following the dissipation of the transmembrane Ca²⁺ gradient by A23187. Time-resolved fluorescence anisotropy of diphenylhexatriene (DPH) has been used to compare the physical state of phospholipids among those proteoliposomes. It is suggested that a proper transmembrane Ca²⁺ gradient is essential for higher membrane fluidity, which may favor G_s function with higher GTP-binding activity and stimulation of adenylate cyclase.

【 授权许可】

Unknown