Keyword search (3,448 papers available)


O4-alkyl-2'-deoxythymidine cross-linked DNA to probe recognition and repair by O6-alkylguanine DNA alkyltransferases.

Author(s): McManus FP, O'Flaherty DK, Noronha AM, Wilds CJ

Org Biomol Chem. 2012 Sep 21;10(35):7078-90 Authors: McManus FP, O'Flaherty DK, Noronha AM, Wilds CJ

Article GUID: 22850722
Preparation of covalently linked complexes between DNA and O(6)-alkylguanine-DNA alkyltransferase using interstrand cross-linked DNA.

Author(s): McManus FP, Khaira A, Noronha AM, Wilds CJ

Bioconjug Chem. 2013 Feb 20;24(2):224-33 Authors: McManus FP, Khaira A, Noronha AM, Wilds CJ

Article GUID: 23347328
Structural basis of interstrand cross-link repair by O6-alkylguanine DNA alkyltransferase.

Author(s): Denisov AY, McManus FP, O'Flaherty DK, Noronha AM, Wilds CJ

Org Biomol Chem. 2017 Oct 11;15(39):8361-8370 Authors: Denisov AY, McManus FP, O'Flaherty DK, Noronha AM, Wilds CJ

Article GUID: 28937154
Altering Residue 134 Confers an Increased Substrate Range of Alkylated Nucleosides to the E. coli OGT Protein.

Author(s): Schoonhoven NM, O'Flaherty DK, McManus FP, Sacre L, Noronha AM, Kornblatt MJ, Wilds CJ

Molecules. 2017 Nov 11;22(11): Authors: Schoonhoven NM, O'Flaherty DK, McManus FP, Sacre L, Noronha AM, Kornblatt MJ, Wilds CJ

Article GUID: 29137116
Title:O4-alkyl-2'-deoxythymidine cross-linked DNA to probe recognition and repair by O6-alkylguanine DNA alkyltransferases.
Authors:McManus FP,  O'Flaherty DK,  Noronha AM,  Wilds CJ
Link:https://www.ncbi.nlm.nih.gov/pubmed/22850722?dopt=Abstract
DOI:10.1039/c2ob25705j
Category:Org Biomol Chem
PMID:22850722
Dept Affiliation: CHEMBIOCHEM
1 Department of Chemistry and Biochemistry, Concordia University, Montreal, Canada.

Description:

O4-alkyl-2'-deoxythymidine cross-linked DNA to probe recognition and repair by O6-alkylguanine DNA alkyltransferases.

Org Biomol Chem. 2012 Sep 21;10(35):7078-90

Authors: McManus FP, O'Flaherty DK, Noronha AM, Wilds CJ

Abstract

DNA duplexes containing a directly opposed O(4)-2'-deoxythymidine-alkyl-O(4)-2'-deoxythymidine (O(4)-dT-alkyl-O(4)-dT) interstrand cross-link (ICL) have been prepared by the synthesis of cross-linked nucleoside dimers which were converted to phosphoramidites to produce site specific ICL. ICL duplexes containing alkyl chains of four and seven methylene groups were prepared and characterized by mass spectrometry and nuclease digests. Thermal denaturation experiments revealed four and seven methylene containing ICL increased the T(m) of the duplex with respect to the non-cross-linked control with an observed decrease in enthalpy based on thermodynamic analysis of the denaturation curves. Circular dichroism experiments on the ICL duplexes indicated minimal difference from B-form DNA structure. These ICL were used for DNA repair studies with O(6)-alkylguanine DNA alkyltransferase (AGT) proteins from human (hAGT) and E. coli (Ada-C and OGT), whose purpose is to remove O(6)-alkylguanine and in some cases O(4)-alkylthymine lesions. It has been previously shown that hAGT can repair O(6)-2'-deoxyguanosine-alkyl-O(6)-2'-deoxyguanosine ICL. The O(4)-dT-alkyl-O(4)-dT ICL prepared in this study were found to evade repair by hAGT, OGT and Ada-C. Electromobility shift assay (EMSA) results indicated that the absence of any repair by hAGT was not a result of binding. OGT was the only AGT to show activity in the repair of oligonucleotides containing the mono-adducts O(4)-butyl-4-ol-2'-deoxythymidine and O(4)-heptyl-7-ol-2'-deoxythymidine. Binding experiments conducted with hAGT demonstrated that the protein bound O(4)-alkylthymine lesions with similar affinities to O(6)-methylguanine, which hAGT repairs efficiently, suggesting the lack of O(4)-alkylthymine repair by hAGT is not a function of recognition.

PMID: 22850722 [PubMed - indexed for MEDLINE]