The interaction of the bisphosphorylated N‐terminal arm of cardiac troponin I‐A 31P‐NMR study

FEBS Letters

Jaquet, Kornelia¹  Schmidtmann, Anja¹  Lohmann, Karin¹ 

[1]Physiologische Chemie, Abt. Biochemie Supramolekularer Systeme, Medizinische Fakultät, Ruhr-Universität Bochum, MA 2/39, 44780 Bochum, Germany

关键词: 31P-Nuclear magnetic resonance;    Cardiac troponin;    Cardiac troponin I;    Cardiac troponin C;    Cardiac troponin T;    ESI-MS;    electrospray ionisation-mass spectrometry;    CD;    circular dichroism;    C-DOM;    C-terminal domain;    hcTn;    human cardiac troponin;    hcTnC;    human cardiac troponin C;    hcTnI;    human cardiac troponin I;    hcTnT;    human cardiac troponin T;    IEF;    isoelectric focusing;    N-DOM;    N-terminal domain;    NMR;    nuclear magnetic resonance;    MOPS;    3-morpholino-propane sulfonic acid;    PKA;    cAMP-dependent protein kinase (protein kinase A);    PP2A;    protein phosphatase 2A;    RMS;    root mean square;    PSer;    phosphoserine residue;    SDS–PAGE;    sodium dodecyl sulphate–polyacrylamide gel electrophoresis;    WT;    wild type;   

DOI  :  10.1016/S0014-5793(02)02340-2

学科分类：生物化学/生物物理

来源: John Wiley & Sons Ltd.

【 摘 要 】

Cardiac troponin I, the inhibitory subunit of the heterotrimeric cardiac troponin (cTn) complex is phosphorylated by protein kinase A at two serine residues located in its heart-specific N-terminal extension. This flexible arm interacts at different sites within cTn dependent on its phosphorylation degree. Bisphosphorylation is known to induce conformational changes within cTnI which finally lead to a reduction of the calcium affinity of cTnC. However, as we show here, the bisphosphorylated cTnI arm does not interact with cTnC, but with cTnT and/or cTnI.

【 授权许可】

Unknown