Protonation of Guanine:5-Methylcytosine and Guanine:Cytosine Base Pairs in Duplex Oligodeoxyribonucleotides

GONZALEZ-OLVERA, Julio C, Radovan FIALA and Reynaldo C PLESS. Protonation of Guanine:5-Methylcytosine and Guanine:Cytosine Base Pairs in Duplex Oligodeoxyribonucleotides. ChemistrySelect. Wiley Online Library, 2022, vol. 7, No 30, p. 202200835-202200846. ISSN 2365-6549. Available from: https://dx.doi.org/10.1002/slct.202200835.

Basic information

• Original name: Protonation of Guanine:5-Methylcytosine and Guanine:Cytosine Base Pairs in Duplex Oligodeoxyribonucleotides
• Authors: GONZALEZ-OLVERA, Julio C, Radovan FIALA (203 Czech Republic, guarantor, belonging to the institution) and Reynaldo C PLESS.
• Edition: ChemistrySelect, Wiley Online Library, 2022, 2365-6549.

Other information

• Original language: English
• Type of outcome: Article in a journal
• Field of Study: 10406 Analytical chemistry
• Country of publisher: Germany
• Confidentiality degree: is not subject to a state or trade secret
• WWW: URL
• Impact factor: Impact factor: 2.100
• RIV identification code: RIV/00216224:14740/22:00127512
• Organization unit: Central European Institute of Technology
• Doi: http://dx.doi.org/10.1002/slct.202200835
• UT WoS: 000837720900001
• Keywords in English: nucleobases; protonation; duplex DNA; oligonucleotides; basicity
• Tags: CF NMR, rivok
• Tags: International impact, Reviewed

Abstract

NMR- and UV-monitored acid titrations conducted on short model oligodeoxyribonucleotide duplexes demonstrate the protonation of guanine:5-methylcytosine and guanine:cytosine base pairs at the O-2 position of the cytosine base, at pH values close to 7, without disruption of the general duplex structure. In the NMR technique, this protonation transition is most clearly observed by monitoring the 5-methylcytosine-H6 resonance, while pH effects on the 5-methylcytosine methyl group, on guanine-H8, and on the cytosine-H5 and -H6 resonances are small. The local sequences G(Me)CG, (TCT)-C-Me, and TCT show decreasing basicity, in this order. The basicity of the G:C-Me base pair is almost unaffected by ionic strength. Under more acidic conditions, adenine:thymine base pairs may be similarly protonated at the adenine base. Hydrogens on thymine bases contained in single-stranded oligonucleotides are strongly affected by the protonation of near-by bases. The results posit that canonical double-stranded DNA is protonated to a significant extent at certain sites under physiological conditions.

Links

• LM2018127, research and development project: Name: Česká infrastruktura pro integrativní strukturní biologii (Acronym: CIISB)

Investor: Ministry of Education, Youth and Sports of the CR