Porphyrin binding mechanism is altered by protonation at the loops in G-quadruplex DNA formed near the transcriptional activation site of the human c-kit gene

Background: G-quadruplex DNA structures are hypothesized to be involved in the regulation of gene expression and telomere homeostasis. The development of small molecules that modulate the stability of G-quadruplex structures has a potential therapeutic interest in cancer treatment and prevention of...

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Autores: Manaye, Sintayehu, Eritja Casadellà, Ramón, Aviñó, Anna, Jaumot, Joaquim, Gargallo, Raimundo
Tipo de recurso: artículo
Estado:Versión aceptada para publicación
Fecha de publicación:2012
País:España
Institución:Consejo Superior de Investigaciones Científicas (CSIC)
Repositorio:DIGITAL.CSIC. Repositorio Institucional del CSIC
OAI Identifier:oai:digital.csic.es:10261/136643
Acceso en línea:http://hdl.handle.net/10261/136643
Access Level:acceso abierto
Palabra clave:C-kit
Conformational analysis
Ligand
G-quadruplex
Multivariate analysis
Stacking interactions
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spelling Porphyrin binding mechanism is altered by protonation at the loops in G-quadruplex DNA formed near the transcriptional activation site of the human c-kit gene Manaye, Sintayehu Eritja Casadellà, Ramón Aviñó, Anna Jaumot, Joaquim Gargallo, Raimundo C-kit Conformational analysis Ligand G-quadruplex Multivariate analysis Stacking interactions Background: G-quadruplex DNA structures are hypothesized to be involved in the regulation of gene expression and telomere homeostasis. The development of small molecules that modulate the stability of G-quadruplex structures has a potential therapeutic interest in cancer treatment and prevention of aging. Methods: Molecular absorption and circular dichroism spectra were used to monitor thermal denaturation, acid base titration and mole ratio experiments. The resulting data were analyzed by multivariate data analysis methods. Surface plasmon resonance was also used to probe the kinetics and affinity of the DNA-drug interactions. Results: We investigated the interaction between a G-quadruplex-forming sequence in the human c-kit proto-oncogene and the water soluble porphyrin TMPyP4. The role of cytosine and adenine residues at the loops of G-quadruplex was studied by substitution of these residues by thymidines. Conclusions: Here, we show the existence of two binding modes between TMPyP4 and the considered G-quadruplex. The stronger binding mode (formation constant around 107) involves end-stacking, while the weaker binding mode (formation constant around 106) is probably due to external loop binding. Evidence for the release of TMPyP4 upon protonation of bases at the loops has been observed. General significance: The results may be used for the design of porphyrin-based anti-cancer molecules with a higher affinity to G-quadruplex structures which may have anticancer properties. © 2012 Elsevier B.V. This research was supported by the Spanish Ministerio de Ciencia e Innovación (grant numbers CTQ2009-11572 and CTQ2010-20541-C03-01), and the Generalitat de Catalunya (grant numbers 2009-SGR-45 and 2009- SGR-208). Peer reviewed Elsevier http://hdl.handle.net/10261/136643
title Porphyrin binding mechanism is altered by protonation at the loops in G-quadruplex DNA formed near the transcriptional activation site of the human c-kit gene
spellingShingle Porphyrin binding mechanism is altered by protonation at the loops in G-quadruplex DNA formed near the transcriptional activation site of the human c-kit gene
Manaye, Sintayehu
C-kit
Conformational analysis
Ligand
G-quadruplex
Multivariate analysis
Stacking interactions
title_short Porphyrin binding mechanism is altered by protonation at the loops in G-quadruplex DNA formed near the transcriptional activation site of the human c-kit gene
title_full Porphyrin binding mechanism is altered by protonation at the loops in G-quadruplex DNA formed near the transcriptional activation site of the human c-kit gene
title_fullStr Porphyrin binding mechanism is altered by protonation at the loops in G-quadruplex DNA formed near the transcriptional activation site of the human c-kit gene
title_full_unstemmed Porphyrin binding mechanism is altered by protonation at the loops in G-quadruplex DNA formed near the transcriptional activation site of the human c-kit gene
title_sort Porphyrin binding mechanism is altered by protonation at the loops in G-quadruplex DNA formed near the transcriptional activation site of the human c-kit gene
author Manaye, Sintayehu
author_facet Manaye, Sintayehu
Eritja Casadellà, Ramón
Aviñó, Anna
Jaumot, Joaquim
Gargallo, Raimundo
author_role author
author2 Eritja Casadellà, Ramón
Aviñó, Anna
Jaumot, Joaquim
Gargallo, Raimundo
author2_role author
author
author
author
topic C-kit
Conformational analysis
Ligand
G-quadruplex
Multivariate analysis
Stacking interactions
topic_facet C-kit
Conformational analysis
Ligand
G-quadruplex
Multivariate analysis
Stacking interactions
description Background: G-quadruplex DNA structures are hypothesized to be involved in the regulation of gene expression and telomere homeostasis. The development of small molecules that modulate the stability of G-quadruplex structures has a potential therapeutic interest in cancer treatment and prevention of aging. Methods: Molecular absorption and circular dichroism spectra were used to monitor thermal denaturation, acid base titration and mole ratio experiments. The resulting data were analyzed by multivariate data analysis methods. Surface plasmon resonance was also used to probe the kinetics and affinity of the DNA-drug interactions. Results: We investigated the interaction between a G-quadruplex-forming sequence in the human c-kit proto-oncogene and the water soluble porphyrin TMPyP4. The role of cytosine and adenine residues at the loops of G-quadruplex was studied by substitution of these residues by thymidines. Conclusions: Here, we show the existence of two binding modes between TMPyP4 and the considered G-quadruplex. The stronger binding mode (formation constant around 107) involves end-stacking, while the weaker binding mode (formation constant around 106) is probably due to external loop binding. Evidence for the release of TMPyP4 upon protonation of bases at the loops has been observed. General significance: The results may be used for the design of porphyrin-based anti-cancer molecules with a higher affinity to G-quadruplex structures which may have anticancer properties. © 2012 Elsevier B.V.
publishDate 2012
format article
status_str acceptedVersion
url http://hdl.handle.net/10261/136643
eu_rights_str_mv openAccess
publisher Elsevier
institution Consejo Superior de Investigaciones Científicas (CSIC)
collection DIGITAL.CSIC. Repositorio Institucional del CSIC
reponame_str DIGITAL.CSIC. Repositorio Institucional del CSIC
instname_str Consejo Superior de Investigaciones Científicas (CSIC)
_version_ 1878442323435585536
publishDateSort 2012
author_browse Aviñó, Anna
Eritja Casadellà, Ramón
Gargallo, Raimundo
Jaumot, Joaquim
Manaye, Sintayehu
publisherStr Elsevier
score 6,9303427

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