High‐affinity Ca2+‐binding site inhibiting Ca2+ release from sarcoplasmic reticulum

FEBS Letters

Argaman, Anat¹  Shoshan-Barmatz, Varda¹ 

[1] Department of Biology, Ben Gurion University of the Negev, Beer Sheva 84105, Israel

关键词: Sarcoplasmic reticulum;    Ca2+ release;    DCCD;    N;    N′-dicyclohexyl carbodiimide;    Tricine;    N-[2-hydroxy-1;    1-bis-(hydroxy-methyl)ethyl]glycine Mops;    3-(N-morpholino)propanesulfonic acid;    CDTA;    trans-1;    2-diamino-cyclohexane-N;    N;    N′;    N′-tetraacetic acid;    RR;    ruthenium red;    TPB−;    tetraphenylboron;    SR;    sarcoplasmic reticulum;   

DOI  :  10.1016/0014-5793(89)81223-2

学科分类：生物化学/生物物理

来源: John Wiley & Sons Ltd.

【 摘 要 】

Ca²⁺ release from sarcoplasmic reticulum membranes, activated by alkaline pH occurs only when EGTA is present in the release medium. Addition of very low concentrations of Ca²⁺ to the medium inhibits Ca²⁺ release. The concentration of free Ca²⁺ required for 50% inhibition ranges from between 5 and 20 nM in different experiments and/or membrane preparations, irrespective of whether the free Ca²⁺ concentration is controlled by EGTA or CDTA. Other divalent cations such as Mn²⁺, Ba²⁺, Cu²⁺, Cd²⁺ and Mg²⁺ also exert an inhibitory effect on Ca²⁺ release, with higher or lower potency than that of Ca²⁺. The inactivation of Ca²⁺ release by Ca²⁺ is reversible. We suggest the involvement of high-affinity Ca²⁺-binding sites in the control of Ca²⁺ release.

【 授权许可】

Unknown