NMR analysis of cardiac troponin C‐troponin I complexes: effects of phosphorylation
1999; Wiley; Volume: 453; Issue: 1-2 Linguagem: Inglês
10.1016/s0014-5793(99)00693-6
ISSN1873-3468
AutoresNatosha L. Finley, M.Bret Abbott, Ekram Abusamhadneh, Vadim Gaponenko, Wen‐Ji Dong, Geneviève M. C. Gasmi-Seabrook, Jack W. Howarth, Mark Rance, R. John Solaro, Herbert C. Cheung, Paul R. Rosevear,
Tópico(s)Cardiomyopathy and Myosin Studies
ResumoPhosphorylation of the cardiac specific amino‐terminus of troponin I has been demonstrated to reduce the Ca 2+ affinity of the cardiac troponin C regulatory site. Recombinant N‐terminal cardiac troponin I proteins, cardiac troponin I(33–80), cardiac troponin I(1–80), cardiac troponin I(1–80)DD and cardiac troponin I(1–80)pp, phosphorylated by protein kinase A, were used to form stable binary complexes with recombinant cardiac troponin C. Cardiac troponin I(1–80)DD, having phosphorylated Ser residues mutated to Asp, provided a stable mimetic of the phosphorylated state. In all complexes, the N‐terminal domain of cardiac troponin I primarily makes contact with the C‐terminal domain of cardiac troponin C. The non‐phosphorylated cardiac specific amino‐terminus, cardiac troponin I(1–80), was found to make additional interactions with the N‐terminal domain of cardiac troponin C.
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