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γ-Hydroxy-1,N(2)-propano-2′-deoxyguanosine DNA Adduct Conjugates the N-Terminal Amine of the KWKK Peptide via a Carbinolamine Linkage

[Image: see text] The γ-hydroxy-1,N(2)-propano-2′-deoxyguanosine adduct (γ-OH-PdG) was introduced into 5′-d(GCTAGCXAGTCC)-3′·5′-d(GGACTCGCTAGC)-3′ (X = γ-OH-PdG). In the presence of excess peptide KWKK, (13)C isotope-edited NMR revealed the formation of two spectroscopically distinct DNA–KWKK conjug...

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Autores principales: Huang, Hai, Wang, Hao, Voehler, Markus W., Kozekova, Albena, Rizzo, Carmelo J., McCullough, Amanda K., Lloyd, R. Stephen, Stone, Michael P.
Formato: Online Artículo Texto
Lenguaje:English
Publicado: American Chemical Society 2011
Acceso en línea:https://www.ncbi.nlm.nih.gov/pmc/articles/PMC3138414/
https://www.ncbi.nlm.nih.gov/pubmed/21561113
http://dx.doi.org/10.1021/tx200113n
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author Huang, Hai
Wang, Hao
Voehler, Markus W.
Kozekova, Albena
Rizzo, Carmelo J.
McCullough, Amanda K.
Lloyd, R. Stephen
Stone, Michael P.
author_facet Huang, Hai
Wang, Hao
Voehler, Markus W.
Kozekova, Albena
Rizzo, Carmelo J.
McCullough, Amanda K.
Lloyd, R. Stephen
Stone, Michael P.
author_sort Huang, Hai
collection PubMed
description [Image: see text] The γ-hydroxy-1,N(2)-propano-2′-deoxyguanosine adduct (γ-OH-PdG) was introduced into 5′-d(GCTAGCXAGTCC)-3′·5′-d(GGACTCGCTAGC)-3′ (X = γ-OH-PdG). In the presence of excess peptide KWKK, (13)C isotope-edited NMR revealed the formation of two spectroscopically distinct DNA–KWKK conjugates. These involved the reaction of the KWKK N-terminal amino group with the N(2)-dG propylaldehyde tautomer of the γ-OH-PdG lesion. The guanine N1 base imino resonance at the site of conjugation was observed in isotope-edited (15)N NMR experiments, suggesting that the conjugated guanine was inserted into the duplex and that the guanine imino proton was protected from exchange with water. The conjugates could be reduced in the presence of NaCNBH(3), suggesting that they existed, in part, as imine (Schiff base) linkages. However, (13)C isotope-edited NMR failed to detect the imine linkages, suggesting that these KWKK conjugates existed predominantly as diastereomeric carbinolamines, in equilibrium with trace amounts of the imines. The structures of the diastereomeric DNA–KWKK conjugates were predicted from potential energy minimization of model structures derived from the refined structure of the fully reduced cross-link [Huang, H., Kozekov, I. D., Kozekova, A., Rizzo, C. J., McCullough, A., Lloyd, R. S., and Stone, M. P. (2010) Biochemistry, 24, 6155−6164]. Molecular dynamics calculations carried out in explicit solvent suggested that the conjugate bearing the S-carbinolamine linkage was the major species due to its potential for intramolecular hydrogen bonding. These carbinolamine DNA–KWKK conjugates thermally stabilized duplex DNA. However, the DNA–KWKK conjugates were chemically reversible and dissociated when the DNA was denatured. In this 5′-CpX-3′ sequence, the DNA–KWKK conjugates slowly converted to interstrand N(2)-dG:N(2)-dG DNA cross-links and ring-opened γ-OH-PdG derivatives over a period of weeks.
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spelling pubmed-31384142011-07-18 γ-Hydroxy-1,N(2)-propano-2′-deoxyguanosine DNA Adduct Conjugates the N-Terminal Amine of the KWKK Peptide via a Carbinolamine Linkage Huang, Hai Wang, Hao Voehler, Markus W. Kozekova, Albena Rizzo, Carmelo J. McCullough, Amanda K. Lloyd, R. Stephen Stone, Michael P. Chem Res Toxicol [Image: see text] The γ-hydroxy-1,N(2)-propano-2′-deoxyguanosine adduct (γ-OH-PdG) was introduced into 5′-d(GCTAGCXAGTCC)-3′·5′-d(GGACTCGCTAGC)-3′ (X = γ-OH-PdG). In the presence of excess peptide KWKK, (13)C isotope-edited NMR revealed the formation of two spectroscopically distinct DNA–KWKK conjugates. These involved the reaction of the KWKK N-terminal amino group with the N(2)-dG propylaldehyde tautomer of the γ-OH-PdG lesion. The guanine N1 base imino resonance at the site of conjugation was observed in isotope-edited (15)N NMR experiments, suggesting that the conjugated guanine was inserted into the duplex and that the guanine imino proton was protected from exchange with water. The conjugates could be reduced in the presence of NaCNBH(3), suggesting that they existed, in part, as imine (Schiff base) linkages. However, (13)C isotope-edited NMR failed to detect the imine linkages, suggesting that these KWKK conjugates existed predominantly as diastereomeric carbinolamines, in equilibrium with trace amounts of the imines. The structures of the diastereomeric DNA–KWKK conjugates were predicted from potential energy minimization of model structures derived from the refined structure of the fully reduced cross-link [Huang, H., Kozekov, I. D., Kozekova, A., Rizzo, C. J., McCullough, A., Lloyd, R. S., and Stone, M. P. (2010) Biochemistry, 24, 6155−6164]. Molecular dynamics calculations carried out in explicit solvent suggested that the conjugate bearing the S-carbinolamine linkage was the major species due to its potential for intramolecular hydrogen bonding. These carbinolamine DNA–KWKK conjugates thermally stabilized duplex DNA. However, the DNA–KWKK conjugates were chemically reversible and dissociated when the DNA was denatured. In this 5′-CpX-3′ sequence, the DNA–KWKK conjugates slowly converted to interstrand N(2)-dG:N(2)-dG DNA cross-links and ring-opened γ-OH-PdG derivatives over a period of weeks. American Chemical Society 2011-05-11 2011-07-18 /pmc/articles/PMC3138414/ /pubmed/21561113 http://dx.doi.org/10.1021/tx200113n Text en Copyright © 2011 American Chemical Society http://pubs.acs.org This is an open-access article distributed under the ACS AuthorChoice Terms & Conditions. Any use of this article, must conform to the terms of that license which are available at http://pubs.acs.org.
spellingShingle Huang, Hai
Wang, Hao
Voehler, Markus W.
Kozekova, Albena
Rizzo, Carmelo J.
McCullough, Amanda K.
Lloyd, R. Stephen
Stone, Michael P.
γ-Hydroxy-1,N(2)-propano-2′-deoxyguanosine DNA Adduct Conjugates the N-Terminal Amine of the KWKK Peptide via a Carbinolamine Linkage
title γ-Hydroxy-1,N(2)-propano-2′-deoxyguanosine DNA Adduct Conjugates the N-Terminal Amine of the KWKK Peptide via a Carbinolamine Linkage
title_full γ-Hydroxy-1,N(2)-propano-2′-deoxyguanosine DNA Adduct Conjugates the N-Terminal Amine of the KWKK Peptide via a Carbinolamine Linkage
title_fullStr γ-Hydroxy-1,N(2)-propano-2′-deoxyguanosine DNA Adduct Conjugates the N-Terminal Amine of the KWKK Peptide via a Carbinolamine Linkage
title_full_unstemmed γ-Hydroxy-1,N(2)-propano-2′-deoxyguanosine DNA Adduct Conjugates the N-Terminal Amine of the KWKK Peptide via a Carbinolamine Linkage
title_short γ-Hydroxy-1,N(2)-propano-2′-deoxyguanosine DNA Adduct Conjugates the N-Terminal Amine of the KWKK Peptide via a Carbinolamine Linkage
title_sort γ-hydroxy-1,n(2)-propano-2′-deoxyguanosine dna adduct conjugates the n-terminal amine of the kwkk peptide via a carbinolamine linkage
url https://www.ncbi.nlm.nih.gov/pmc/articles/PMC3138414/
https://www.ncbi.nlm.nih.gov/pubmed/21561113
http://dx.doi.org/10.1021/tx200113n
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