Evaluation of the structure–activity relationship of thrombin with thrombin binding aptamers by voltammetry and atomic force microscopy

The structure–activity relationship of the complex between thrombin and thrombin binding aptamers (TBA) was evaluated by differential pulse voltammetry at a glassy carbon electrode and atomic force microscopy at a highly oriented pyrolytic graphite electrode. The effects on the interaction with thro...

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Detalles Bibliográficos
Autores: Diculescu, Victor Constantin, Chiorcea-Paquim, Ana-Maria, Eritja Casadellà, Ramón, Oliveira-Brett, Ana Maria
Tipo de recurso: artículo
Estado:Versión aceptada para publicación
Fecha de publicación:2011
País:España
Institución:Consejo Superior de Investigaciones Científicas (CSIC)
Repositorio:DIGITAL.CSIC. Repositorio Institucional del CSIC
OAI Identifier:oai:digital.csic.es:10261/48054
Acceso en línea:http://hdl.handle.net/10261/48054
Access Level:acceso abierto
Palabra clave:Thrombin
Aptamers
Quadruplex
Guanine
AFM
Electrochemistry
Descripción
Sumario:The structure–activity relationship of the complex between thrombin and thrombin binding aptamers (TBA) was evaluated by differential pulse voltammetry at a glassy carbon electrode and atomic force microscopy at a highly oriented pyrolytic graphite electrode. The effects on the interaction with thrombin of TBA primary and secondary structures as well as of its folding properties in the presence of alkaline metals were investigated. The complex between thrombin and single stranded aptamers involved the coiling of the single stranded molecules around thrombin structure leading to the formation of a robust TBA–thrombin complex that maintains the symmetry and conformation of the thrombin molecule. Monitoring both thrombin and TBA oxidation peaks, showed that the thrombin oxidation peaks occur at more positive potentials after TBA–thrombin complex formation. In the presence of K+ ions, the aptamers fold into quadruplex structures that facilitate the interaction with thrombin molecules. The TBA–thrombin complex adsorbs at the surface with the aptamer quadruplex always in preferential contact with the surface, and the thrombin molecules on top of the aptamer quadruplex structure, thus being less accessible to the electrode surface leading to the occurrence of thrombin oxidation peaks at less positive potentials.