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Spin-labeled derivatives of cardiotonic steroids as tools for characterization of the extracellular entrance to the binding site on Na+,K+-ATPase
- Source :
- Guo, J-H, Jiang, R-W, Andersen, J L, Esmann, M & Fedosova, N 2018, ' Spin-labeled derivatives of cardiotonic steroids as tools for characterization of the extracellular entrance to the binding site on Na+,K+-ATPase ', F E B S Journal, vol. 285, no. 12, pp. 2292-2305 . https://doi.org/10.1111/febs.14480
- Publication Year :
- 2018
-
Abstract
- The information obtained from crystallized complexes of the Na + ,K + -ATPase with cardiotonic steroids (CTS) is not sufficient to explain differences in the inhibitory properties of CTS such as stereoselectivity of CTS binding or effect of glycosylation on the preference to enzyme isoforms. The uncertainty is related to the spatial organization of the hydrophilic cavity at the entrance of the CTS-binding site. Therefore, there is a need to supplement the crystallographic description with data obtained in aqueous solution, where molecules have significant degree of flexibility. This work addresses the applicability of the electron paramagnetic resonance (EPR) method for the purpose. We have designed and synthesized spin-labeled compounds based on the cinobufagin steroid core. The length of the spacer arms between the steroid core and the nitroxide group determines the position of the reporting group (N-O) confined to the binding site. High affinity to Na + ,K + -ATPase is inferred from their ability to inhibit enzymatic activity. The differences between the EPR spectra in the absence and presence of high ouabain concentrations identify the signature peaks originating from the fraction of the spin labels bound within the ouabain site. The degree of perturbations of the EPR spectra depends on the length of the spacer arm. Docking of the compounds into the CTS site suggests which elements of the protein structure might be responsible for interference with the spin label (e.g., steric clashes or immobilization). Thus, the method is suitable for gathering information on the cavity leading to the CTS-binding site in Na + ,K + -ATPase in all conformations with high affinity to CTS.
- Subjects :
- 0301 basic medicine
Swine
ATPase
Kidney
Ligands
Biochemistry
Protein Structure, Secondary
Ouabain
law.invention
0302 clinical medicine
Protein structure
law
Na pump
membrane protein
Spin label
Electron paramagnetic resonance
biology
Chemistry
Cations, Monovalent
Molecular Docking Simulation
030220 oncology & carcinogenesis
Thermodynamics
Sodium-Potassium-Exchanging ATPase
protein–ligand interactions
Protein Binding
medicine.drug
Cardiotonic Agents
Stereochemistry
Cardiac Glycosides
Structure-Activity Relationship
03 medical and health sciences
medicine
Animals
Protein Interaction Domains and Motifs
Na+/K+-ATPase
Binding site
Molecular Biology
Binding Sites
Sodium
Electron Spin Resonance Spectroscopy
Structure
Cell Biology
nervous system diseases
Bufanolides
Kinetics
030104 developmental biology
Docking (molecular)
Amphibian Venoms
Potassium
biology.protein
Spin Labels
EPR
Subjects
Details
- Language :
- English
- Database :
- OpenAIRE
- Journal :
- Guo, J-H, Jiang, R-W, Andersen, J L, Esmann, M & Fedosova, N 2018, ' Spin-labeled derivatives of cardiotonic steroids as tools for characterization of the extracellular entrance to the binding site on Na+,K+-ATPase ', F E B S Journal, vol. 285, no. 12, pp. 2292-2305 . https://doi.org/10.1111/febs.14480
- Accession number :
- edsair.doi.dedup.....eb096953d6a80c780074a3b97608eb06