Thermodynamics of the multi-stage DNA lesion recognition and repair by Formamidopyrimidine-DNA glycosylase using pyrrolocytosine fluorescence - Stopped-flow pre-steady-state kinetics

Document Type

Article

Publication Date

8-1-2012

Abstract

Formamidopyrimidine-DNA glycosylase, Fpg protein from Escherichia coli, initiates base excision repair in DNA by removing a wide variety of oxidized lesions. In this study, we perform thermodynamic analysis of the multi-stage interaction of Fpg with specific DNA-substrates containing 7,8-dihydro-8- oxoguanosine (oxoG), or tetrahydrofuran (THF, an uncleavable abasic site analog) and non-specific (G) DNA-ligand based on stopped-flow kinetic data. Pyrrolocytosine, highly fluorescent analog of the natural nucleobase cytosine, is used to record multi-stage DNA lesion recognition and repair kinetics over a temperature range (10-30°C). The kinetic data were used to obtain the standard Gibbs energy, enthalpy and entropy of the specific stages using van't Hoff approach. The data suggest that not only enthalpy-driven exothermic oxoG recognition, but also the desolvation-accompanied entropy-driven enzyme-substrate complex adjustment into the catalytically active state play equally important roles in the overall process. © The Author(s) 2012.

Identifier

84867298594 (Scopus)

Publication Title

Nucleic Acids Research

External Full Text Location

https://doi.org/10.1093/nar/gks423

e-ISSN

13624962

ISSN

03051048

PubMed ID

22584623

First Page

7384

Last Page

7392

Issue

15

Volume

40

Grant

10-04-00070

Fund Ref

Russian Foundation for Basic Research

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