The effect of troponin C removal on the Ca2+‐sensitive binding of Mg2+AMPPNP to myofibrils

FEBS Letters

Johnson, Robert E.¹ 

[1] University Department of Biochemistry, University of Arizona, Tucson, AZ 85721, USA

关键词: Myofibril;    Troponin C;    Actin-myosin interaction;    AMPPNP;    S-1;    myosin subfragment 1;    AMPPNP;    adenosyl-5′-yl imidodiphosphate;    Ap5A;    P1;    P5-di(adenosine 5′)-pentaphosphate;   

DOI  :  10.1016/0014-5793(88)80755-5

学科分类：生物化学/生物物理

来源: John Wiley & Sons Ltd.

【 摘 要 】

It was previously shown that when rabbit skeletal myofibrils are titrated with Mg²⁺ AMPPNP under conditions that result in the dissociation of cross-bridges from the thin filaments (i.e. 50% ethylene glycol, O°C), Ca²⁺-sensitive, biphasic binding is observed. These titrations have been repeated using myofibrils from which the troponin C has been selectively removed. The disappearance of both Ca²⁺ sensitivity and biphasic binding is taken as evidence that the Ca²⁺ sensitivity is due to Ca²⁺ binding to troponin C and the biphasic binding of Mg²⁺AMPPNP observed in intact myofibrils is not due to packing constraints or steric hindrance.

【 授权许可】

Unknown