1IH0

Structure of the C-domain of Human Cardiac Troponin C in Complex with Ca2+ Sensitizer EMD 57033


Experimental Data Snapshot

  • Method: SOLUTION NMR
  • Conformers Calculated: 30 
  • Conformers Submitted: 30 
  • Selection Criteria: all calculated structures submitted 

wwPDB Validation 3D Report Full Report


This is version 1.2 of the entry. See complete history

Literature

Structure of the C-domain of human cardiac troponin C in complex with the Ca2+ sensitizing drug EMD 57033.

Wang, X.Li, M.X.Spyracopoulos, L.Beier, N.Chandra, M.Solaro, R.J.Sykes, B.D.

(2001) J.Biol.Chem. 276: 25456-25466

  • DOI: 10.1074/jbc.M102418200

  • PubMed Abstract: 
  • Ca(2+) binding to cardiac troponin C (cTnC) triggers contraction in heart muscle. In heart failure, myofilaments response to Ca(2+) are often altered and compounds that sensitize the myofilaments to Ca(2+) possess therapeutic value in this syndrome. ...

    Ca(2+) binding to cardiac troponin C (cTnC) triggers contraction in heart muscle. In heart failure, myofilaments response to Ca(2+) are often altered and compounds that sensitize the myofilaments to Ca(2+) possess therapeutic value in this syndrome. One of the most potent and selective Ca(2+) sensitizers is the thiadiazinone derivative EMD 57033, which increases myocardial contractile function both in vivo and in vitro and interacts with cTnC in vitro. We have determined the NMR structure of the 1:1 complex between Ca(2+)-saturated C-domain of human cTnC (cCTnC) and EMD 57033. Favorable hydrophobic interactions between the drug and the protein position EMD 57033 in the hydrophobic cleft of the protein. The drug molecule is orientated such that the chiral group of EMD 57033 fits deep in the hydrophobic pocket and makes several key contacts with the protein. This stereospecific interaction explains why the (-)-enantiomer of EMD 57033 is inactive. Titrations of the cCTnC.EMD 57033 complex with two regions of cardiac troponin I (cTnI(34-71) and cTnI(128-147)) reveal that the drug does not share a common binding epitope with cTnI(128-147) but is completely displaced by cTnI(34-71). These results have important implications for elucidating the mechanism of the Ca(2+) sensitizing effect of EMD 57033 in cardiac muscle contraction.


    Organizational Affiliation

    CIHR Group in Protein Structure and Function, Department of Biochemistry, University of Alberta, Edmonton, Alberta T6G 2H7, Canada.




Macromolecules

Find similar proteins by: Sequence  |  Structure

Entity ID: 1
MoleculeChainsSequence LengthOrganismDetails
TROPONIN C, SLOW SKELETAL AND CARDIAC MUSCLES
A
71Homo sapiensMutation(s): 0 
Gene Names: TNNC1 (TNNC)
Find proteins for P63316 (Homo sapiens)
Go to Gene View: TNNC1
Go to UniProtKB:  P63316
Small Molecules
Ligands 2 Unique
IDChainsName / Formula / InChI Key2D Diagram3D Interactions
CA
Query on CA

Download SDF File 
Download CCD File 
A
CALCIUM ION
Ca
BHPQYMZQTOCNFJ-UHFFFAOYSA-N
 Ligand Interaction
EMD
Query on EMD

Download SDF File 
Download CCD File 
A
5-[1-(3,4-DIMETHOXY-BENZOYL)-1,2,3,4-TETRAHYDRO-QUINOLIN-6-YL]-6-METHYL-3,6-DIHYDRO-[1,3,4]THIADIAZIN-2-ONE
C22 H23 N3 O4 S
IZLRMTJLQCLMKF-CYBMUJFWSA-N
 Ligand Interaction
External Ligand Annotations 
IDBinding Affinity (Sequence Identity %)
EMDKd: 10000 nM PDBBIND
Experimental Data & Validation

Experimental Data

  • Method: SOLUTION NMR
  • Conformers Calculated: 30 
  • Conformers Submitted: 30 
  • Selection Criteria: all calculated structures submitted 
  • Olderado: 1IH0 Olderado

Structure Validation

View Full Validation Report or Ramachandran Plots



Entry History 

Deposition Data

Revision History 

  • Version 1.0: 2001-10-10
    Type: Initial release
  • Version 1.1: 2008-04-27
    Type: Version format compliance
  • Version 1.2: 2011-07-13
    Type: Version format compliance