Conformational changes in the metal-binding sites of cardiac troponin C induced by calcium binding

Biochemistry ◽  
1992 ◽  
Vol 31 (6) ◽  
pp. 1595-1602 ◽  
Author(s):  
George A. Krudy ◽  
Rui M. M. Brito ◽  
John A. Putkey ◽  
Paul R. Rosevear
Keyword(s):  
Conformational Changes ◽  
Metal Binding ◽  
Binding Sites ◽  
Calcium Binding ◽  
Cardiac Troponin ◽  
Troponin C ◽  
Metal Binding Sites ◽  
Cardiac Troponin C

scholarly journals Mutation of the high affinity calcium binding sites in cardiac troponin C.

1992 ◽  
Vol 267 (2) ◽  
pp. 825-831 ◽  
Author(s):  
J C Negele ◽  
D G Dotson ◽  
W Liu ◽  
H L Sweeney ◽  
J A Putkey
Keyword(s):  
Binding Sites ◽  
Calcium Binding ◽  
Cardiac Troponin ◽  
Troponin C ◽  
High Affinity ◽  
Cardiac Troponin C ◽  
Calcium Binding Sites

scholarly journals The effect of magnesium on calcium binding to cardiac troponin C related hypertrophic cardiomyopathy mutants

2021 ◽  
Author(s):  
Kaveh Rayani ◽  
Eric Hantz ◽  
Omid Haji-Ghassemi ◽  
Alison Yueh Li ◽  
Anne Marie Spuches ◽  
...  
Keyword(s):  
Conformational Changes ◽  
Calcium Binding ◽  
Cardiac Troponin ◽  
Force Production ◽  
Troponin C ◽  
Titration Calorimetry ◽  
Binding Motif ◽  
Binding Interaction ◽  
Cardiac Troponin C ◽  
Potential Competitor

Cardiac troponin C (cTnC) is the calcium (Ca2+) sensing component of the troponin complex. Binding of Ca2+ to cTnC triggers a cascade of myofilament conformational changes that culminate in force production. Mutations in cTnC linked to hypertrophic myocardial myopathy (HCM) induce a greater degree and duration of Ca2+ binding, which may underly the hypertrophic phenotype. Recent evidence from our laboratories demonstrated novel modifications of cTnC Ca2+ binding by cellular magnesium (Mg2+) that we hypothesize may be of significance in promoting HCM.Regulation of contraction has long been thought to occur exclusively through Ca2+ binding to site II of cTnC. However, abundant cellular Mg2+ is a potential competitor for binding to the same sites; work by several groups also suggests this is possible. We have used isothermal titration calorimetry (ITC) to explore the thermodynamic properties associated with the interaction between Ca2+/Mg2+ and site II of cTnC; these experiments demonstrated that physiological concentrations of Mg2+ may compete with Ca2+ to bind site II of cTnC.In experiments reported here, we studied a series of mutations in cTnC thought to be causal in HCM. Three mutants (A8V, L29Q, and A31S) slightly elevated the affinity for both Ca2+ and Mg2+, whereas other mutants (L48Q, Q50R, and C84Y), that are closer to the C-terminal domain and surrounding the EF hand binding motif of site II had a more significant effect on affinity and the thermodynamics of the binding interaction.

scholarly journals Identification of Metal-binding Sites in Rat Brain Calcium-binding Protein

1995 ◽  
Vol 270 (51) ◽  
pp. 30353-30358 ◽  
Author(s):  
Timothy D. Veenstra ◽  
Myron D. Gross ◽  
Willi Hunziker ◽  
Rajiv Kumar
Keyword(s):  
Rat Brain ◽  
Metal Binding ◽  
Binding Sites ◽  
Calcium Binding ◽  
Binding Protein ◽  
Calcium Binding Protein ◽  
Metal Binding Sites
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