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Título:
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Thermodynamic analysis of the binding of 5-fluoro-2'-deoxyuridine 5'-monophosphate to thymidylate synthase over a range of temperatures
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Autores:
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García Fuentes, Luis ;
Reche, Pedro A ;
López Mayorga, O ;
Santi, D V ;
González-Pacanowska, D. ;
Barón, C
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Tipo de documento:
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texto impreso
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Editorial:
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Wiley InterScience, 1995
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Dimensiones:
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application/pdf
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Nota general:
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info:eu-repo/semantics/openAccess
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Idiomas:
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Palabras clave:
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Estado = Publicado
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Materia = Ciencias: Química: Biología molecular
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Materia = Ciencias: Química: Bioquímica
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Tipo = Artículo
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Resumen:
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The binding of 5-fluoro-2'-deoxyuridine 5'-monophosphate (FdUMP) to Lactobacillus casei recombinant thymidylate synthase has been studied by isothermal titration microcalorimetry at pH 7.1 over the temperature range 16-35 degrees C. Calorimetric measurements in various buffer systems with different heats of ionization suggest that a proton uptake is involved in the binding process of the nucleotide. In the temperature range investigated, the mol protons bound/mol nucleotide increases as the temperature decreases. A model of two equal and independent sites fits well with the binding isotherms for thymidylate synthase. The binding constants, the changes in Gibbs energy, enthalpy, and entropy/site for FdUMP binding were calculated at each temperature. The results show that the binding is driven by both enthalpy and entropy contributions in the range 16-35 degrees C. The enthalpy changes become more negative as the temperature increases, with delta Cp = -170 +/- 20 J.K-1.(mol FdUMP bound)-1. The behavior of the system supports the observation that FdUMP binds to thymidylate synthase without producing profound conformational changes in the protein dimer.
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En línea:
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https://eprints.ucm.es/id/eprint/9354/1/03.GarciaF_Reche_etal_EJB_1995.pdf
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