The Solution Structure of Human Cardiac Troponin C in complex with the Green Tea Polyphenol; (-)-epigallocatechin-3-gallate

Experimental Data Snapshot

  • Method: SOLUTION NMR
  • Conformers Calculated: 100 
  • Conformers Submitted: 30 
  • Selection Criteria: structures with the lowest energy 

wwPDB Validation   3D Report Full Report

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Solution structure of human cardiac troponin C in complex with the green tea polyphenol, (-)-epigallocatechin 3-gallate

Robertson, I.M.Li, M.X.Sykes, B.D.

(2009) J Biol Chem 284: 23012-23023

  • DOI: https://doi.org/10.1074/jbc.M109.021352
  • Primary Citation of Related Structures:  

  • PubMed Abstract: 

    Heart muscle contraction is regulated by Ca(2+) binding to the thin filament protein troponin C. In cardiovascular disease, the myofilament response to Ca(2+) is often altered. Compounds that rectify this perturbation are of considerable interest as therapeutics. Plant flavonoids have been found to provide protection against a variety of human illnesses such as cancer, infection, and heart disease. (-)-Epigallocatechin gallate (EGCg), the prevalent flavonoid in green tea, modulates force generation in isolated guinea pig hearts (Hotta, Y., Huang, L., Muto, T., Yajima, M., Miyazeki, K., Ishikawa, N., Fukuzawa, Y., Wakida, Y., Tushima, H., Ando, H., and Nonogaki, T. (2006) Eur. J. Pharmacol. 552, 123-130) and in skinned cardiac muscle fibers (Liou, Y. M., Kuo, S. C., and Hsieh, S. R. (2008) Pflugers Arch. 456, 787-800; and Tadano, N., Yumoto, F., Tanokura, M., Ohtsuki, I., and Morimoto, S. (2005) Biophys. J. 88, 314a). In this study we describe the solution structure of the Ca(2+)-saturated C-terminal domain of troponin C in complex with EGCg. Moreover, we show that EGCg forms a ternary complex with the C-terminal domain of troponin C and the anchoring region of troponin I. The structural evidence indicates that the binding site of EGCg on the C-terminal domain of troponin C is in the hydrophobic pocket in the absence of troponin I, akin to EMD 57033. Based on chemical shift mapping, the binding of EGCg to the C-terminal domain of troponin C in the presence of troponin I may be to a new site formed by the troponin C.troponin I complex. This interaction of EGCg with the C-terminal domain of troponin C.troponin I complex has not been shown with other cardiotonic molecules and illustrates the potential mechanism by which EGCg modulates heart contraction.

  • Organizational Affiliation

    Department of Biochemistry, University of Alberta, Edmonton, Alberta T6G 2H7, Canada.

Find similar proteins by:  (by identity cutoff)  |  3D Structure
Entity ID: 1
MoleculeChains Sequence LengthOrganismDetailsImage
Troponin C, slow skeletal and cardiac muscles72Homo sapiensMutation(s): 0 
Gene Names: TNNC1TNNC
UniProt & NIH Common Fund Data Resources
Find proteins for P63316 (Homo sapiens)
Explore P63316 
Go to UniProtKB:  P63316
PHAROS:  P63316
GTEx:  ENSG00000114854 
Entity Groups  
Sequence Clusters30% Identity50% Identity70% Identity90% Identity95% Identity100% Identity
UniProt GroupP63316
Sequence Annotations
  • Reference Sequence
Small Molecules
Ligands 2 Unique
IDChains Name / Formula / InChI Key2D Diagram3D Interactions
Query on KDH

Download Ideal Coordinates CCD File 
C [auth A](2R,3R)-5,7-dihydroxy-2-(3,4,5-trihydroxyphenyl)-3,4-dihydro-2H-chromen-3-yl 3,4,5-trihydroxybenzoate
C22 H18 O11
Query on CA

Download Ideal Coordinates CCD File 
B [auth A],
D [auth A]
Binding Affinity Annotations 
IDSourceBinding Affinity
KDH PDBBind:  2KDH Kd: 1.10e+6 (nM) from 1 assay(s)
Experimental Data & Validation

Experimental Data

  • Method: SOLUTION NMR
  • Conformers Calculated: 100 
  • Conformers Submitted: 30 
  • Selection Criteria: structures with the lowest energy 

Structure Validation

View Full Validation Report

Entry History 

Deposition Data

Revision History  (Full details and data files)

  • Version 1.0: 2009-06-16
    Type: Initial release
  • Version 1.1: 2011-07-13
    Changes: Version format compliance
  • Version 1.2: 2022-03-16
    Changes: Data collection, Database references, Derived calculations, Structure summary
  • Version 1.3: 2024-05-22
    Changes: Data collection