Limited proteolysis combined with isotope labeling and quantitative LC-MALDI MS for monitoring protein conformational changes: a study on calcium-binding sites of cardiac Troponin C

2005 ◽  
Vol 534 (1) ◽  
pp. 3-10 ◽  
Author(s):  
Chris McDonald ◽  
Liang Li
Keyword(s):  
Conformational Changes ◽  
Binding Sites ◽  
Calcium Binding ◽  
Cardiac Troponin ◽  
Isotope Labeling ◽  
Limited Proteolysis ◽  
Troponin C ◽  
Cardiac Troponin C ◽  
Protein Conformational Changes ◽  
Calcium Binding Sites

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

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

Cardiac Troponin I Induced Conformational Changes in Cardiac Troponin C As Monitored by NMR Using Site-Directed Spin and Isotope Labeling

Biochemistry ◽  
1995 ◽  
Vol 34 (41) ◽  
pp. 13343-13352 ◽  
Author(s):  
Quinn Kleerekoper ◽  
Jack W. Howarth ◽  
Xiaodu Guo ◽  
R. John Solaro ◽  
Paul R. Rosevear
Keyword(s):  
Conformational Changes ◽  
Cardiac Troponin ◽  
Troponin I ◽  
Isotope Labeling ◽  
Troponin C ◽  
Cardiac Troponin I ◽  
Cardiac Troponin C

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 Conformational epitopes at cadherin calcium-binding sites and p120-catenin phosphorylation regulate cell adhesion

2012 ◽  
Vol 23 (11) ◽  
pp. 2092-2108 ◽  
Author(s):  
Yuliya I. Petrova ◽  
MarthaJoy M. Spano ◽  
Barry M. Gumbiner
Keyword(s):  
Cell Surface ◽  
Conformational Changes ◽  
Binding Sites ◽  
Calcium Binding ◽  
Cell Types ◽  
P120 Catenin ◽  
Physiological Regulation ◽  
Conformational Epitopes ◽  
Calcium Binding Sites ◽  
E Cadherin

We investigated changes in cadherin structure at the cell surface that regulate its adhesive activity. Colo 205 cells are nonadhesive cells with a full but inactive complement of E-cadherin–catenin complexes at the cell surface, but they can be triggered to adhere and form monolayers. We were able to distinguish the inactive and active states of E-cadherin at the cell surface by using a special set of monoclonal antibodies (mAbs). Another set of mAbs binds E-cadherin and strongly activates adhesion. In other epithelial cell types these activating mAbs inhibit growth factor–induced down-regulation of adhesion and epithelial morphogenesis, indicating that these phenomena are also controlled by E-cadherin activity at the cell surface. Both types of mAbs recognize conformational epitopes at different interfaces between extracellular cadherin repeat domains (ECs), especially near calcium-binding sites. Activation also induces p120-catenin dephosphorylation, as well as changes in the cadherin cytoplasmic domain. Moreover, phospho-site mutations indicate that dephosphorylation of specific Ser/Thr residues in the N-terminal domain of p120-catenin mediate adhesion activation. Thus physiological regulation of the adhesive state of E-cadherin involves physical and/or conformational changes in the EC interface regions of the ectodomain at the cell surface that are mediated by catenin-associated changes across the membrane.

Sign in / Sign up

Export Citation Format

Share Document