Sarcoplasmic reticulum CaATPase: product inhibition suggests an allosteric site for ATP activation

FEBS Letters

Coll, Richard J.¹  Murphy, Alexander J.¹ 

[1] Department of Biochemistry, University of the Pacific, School of Dentistry, 2155 Webster Street, San Francisco, CA 94115, USA

关键词: Sarcoplasmic reticulum CaATPase Product inhibition Biphasic kinetics Allosteric site;    SR;    sarcoplasmic reticulum;    E-P;    phosphorylated enzyme intermediate;    AMP-PCP;    β;    γ-methyleneadenosine 5 '-triphosphate;    Mops;    3-(N-morpholino)propanesulfonic acid;    Ap5A;    diadenosine pentaphosphate;   

DOI  :  10.1016/0014-5793(85)81228-X

学科分类：生物化学/生物物理

来源: John Wiley & Sons Ltd.

【 摘 要 】

Sarcoplasmic reticulum CaATPase hydrolysis of high concentrations of ATP was studied in the presence of ADP. The results obtained were best described as noncompetitive inhibition; added product lowered the V _max but did not affect the slopes of Eadie-Hofstee plots. At these concentrations (0.5–5 mM), ATP is known to act as both a substrate and as an activator of turnover. The inability of ATP to overcome ADP inhibition suggests that activating ATP binds to an allosteric regulatory site rather than to the phosphorylated active site.

【 授权许可】

Unknown