Role of the Structural Domain of Troponin C in Muscle Regulation:  NMR Studies of Ca2+Binding and Subsequent Interactions with Regions 1−40 and 96−115 of Troponin I†

Biochemistry ◽  
2000 ◽  
Vol 39 (11) ◽  
pp. 2902-2911 ◽  
Author(s):  
Pascal Mercier ◽  
Monica X. Li ◽  
Brian D. Sykes
Keyword(s):  
Troponin I ◽  
Troponin C ◽  
Structural Domain ◽  
Nmr Studies ◽  
Muscle Regulation

The Role of Electrostatics in the Interaction of the Inhibitory Region of Troponin I with Troponin C†

Biochemistry ◽  
2005 ◽  
Vol 44 (45) ◽  
pp. 14750-14759 ◽  
Author(s):  
Darrin A. Lindhout ◽  
Robert F. Boyko ◽  
David C. Corson ◽  
Monica X. Li ◽  
Brian D. Sykes
Keyword(s):  
Troponin I ◽  
Troponin C ◽  
Inhibitory Region

scholarly journals NMR studies delineating spatial relationships within the cardiac troponin I-troponin C complex.

1994 ◽  
Vol 269 (38) ◽  
pp. 23731-23735
Author(s):  
G.A. Krudy ◽  
Q. Kleerekoper ◽  
X. Guo ◽  
J.W. Howarth ◽  
R.J. Solaro ◽  
...  
Keyword(s):  
Cardiac Troponin ◽  
Troponin I ◽  
Troponin C ◽  
Cardiac Troponin I ◽  
Spatial Relationships ◽  
Nmr Studies ◽  
C Complex

Interaction of troponin I and troponin C: 19F NMR studies of the binding of the inhibitory troponin I peptide to turkey skeletal troponin C

1991 ◽  
Vol 69 (9) ◽  
pp. 674-681 ◽  
Author(s):  
A. Patricia Campbell ◽  
Paul J. Cachia ◽  
Brian D. Sykes
Keyword(s):  
Calcium Binding ◽  
Troponin I ◽  
Dissociation Constants ◽  
Chemical Shifts ◽  
Troponin C ◽  
Resonance Spectroscopy ◽  
Nmr Studies ◽  
Binding Model ◽  
Peptide Binding Site ◽  
Titration Data

We have used 19F nuclear magnetic resonance spectroscopy to study the interaction of the inhibitory region of troponin (TnI) with apo- and calcium(II)-saturated turkey skeletal troponin C (TnC), using the synthetic TnI analogue Nα-acetyl[19FPhe106]TnI(104–115)amide. Dissociation constants of Kd = (3.7 ± 3.1) × 10−5 M for the apo interaction and Kd = (4.8 ± 1.8) × 10−5 M for the calcium(II)-saturated interaction were obtained using a 1:1 binding model of peptide to protein. The 19F NMR chemical shifts for the F-phenylalanine of the bound peptide are different from the apo- and calcium-saturated protein, indicating a different environment for the bound peptide. The possibility of 2:1 binding of the peptide to Ca(II)-saturated TnC was tested by calculating the fit of the experimental titration data to a series of theoretical binding curves in which the dissociation constants for the two hypothetical binding sites were varied. We obtained the best fit for 0.056 mM ≤ Kd1 ≤ 0.071 mM and 0.5 mM ≤ Kd2 ≤ 2.0 mM. These results allow the possibility of a second peptide binding site on calcium(II)-saturated TnC with an affinity 10- to 20-fold weaker than that of the first site.Key words: tropinin C, tropinin I, calcium binding, NMR studies, muscle proteins.

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