2024-03-29T14:17:02Zhttps://riubu.ubu.es/oai/requestoai:riubu.ubu.es:10259/47462022-04-29T12:02:48Zcom_10259_4365com_10259_5086com_10259_2604com_10259_4883col_10259_4366col_10259_4884
Kinetic evidence for interaction of TMPyP4 with two different G-quadruplex conformations of human telomeric DNA
Pérez Arnáiz, Cristina
Busto Vázquez, Natalia
Santolaya, Javier
Leal Villalba, José María
Barone, Giampaolo
García Ruiz, Begoña
Tel22 conformations
TMPyP4
Fast reactions
Molecular dynamics
Chemistry, Physical and theoretical
Química física
Background: Stabilization of G-quadruplex helices by small ligands has attracted growing attention because they
inhibit the activity of the enzyme telomerase, which is overexpressed in> 80% cancer cells. TMPyP4, one of the
most studied G-quadruplex ligands, is used as a model to show that the ligands can exhibit different binding
features with different conformations of a human telomeric specific sequence.
Methods: UV–Vis, FRET melting Assay, Isothermal Titration Calorimetry, Time-resolved Fluorescence lifetime,
T-Jump and Molecular Dynamics.
Results: TMPyP4 yields two different complexes with two Tel22 telomeric conformations in the presence of Na+
or K+. T-Jump kinetic experiments show that the rates of formation and dissociation of these complexes in the
ms time scale differ by one order of magnitude. MD simulations reveal that, in K+ buffer, “hybrid 1” conformation
yields kinetic constants on interaction with TMPyP4 one order lower than “hybrid 2”. The binding
involves π–π stacking with external loop bases.
Conclusions: For the first time we show that for a particular buffer TMPyP4 interacts in a kinetically different
way with the two Tel22 conformations even if the complexes formed are thermodynamically indistinguishable.
General significance: G-quadruplexes, endowed with technological applications and potential impact on regulation
mechanisms, define a new research field. The possibility of building different conformations from same
sequence is a complex issue that confers G-quadruplexes very interesting features. The obtaining of reliable
kinetic data constitutes an efficient tool to determine reaction mechanisms between conformations and small
molecules.
“la
Caixa” Foundation (project OSLC-2012-007), MINECO, (CTQ2014-
58812-C2-2-R) and Junta de Castilla y León, (BU042U16), FEDER
Funds Spain
2018-03-08T09:23:37Z
2019-03-01T03:45:06Z
2018-03
info:eu-repo/semantics/article
info:eu-repo/semantics/acceptedVersion
0304-4165
http://hdl.handle.net/10259/4746
10.1016/j.bbagen.2017.10.020
eng
Biochimica et biophysica acta (BBA) - general subjects. 2018, V. 1862, n. 3, p. 522-531
https://doi.org/10.1016/j.bbagen.2017.10.020
info:eu-repo/grantAgreement/“la
Caixa” Foundation/OSLC-2012-007
info:eu-repo/grantAgreement/MINECO/CTQ2014-58812-C2-2-R
info:eu-repo/grantAgreement/JCyL/BU042U16
Attribution-NonCommercial-NoDerivatives 4.0 International
http://creativecommons.org/licenses/by-nc-nd/4.0/
info:eu-repo/semantics/openAccess
application/pdf
Elsevier