Spectroscopic study of protonation of oligonucleotides containing adenine and cytosine
| Authors | |
|---|---|
| Year of publication | 2009 |
| Type | Article in Periodical |
| Magazine / Source | Chem. Papers |
| MU Faculty or unit | |
| Citation | |
| Web | http://www.springerlink.com/content/b163418v38432172/?p=afb907946c874228a3c45a57420400e5&pi=15 |
| Field | Analytic chemistry |
| Keywords | oligonucleotides; adenine; cytosine; protonation; thermodynamics; chemometrics |
| Description | Acidobasic properties of purine and pyrimidine bases (adenine, cytosine) and relevant nucleosides (adenosine, cytidine) were studied by means of glass-electrode potentiometry and the respective dissociation constants were determined under given experimental conditions (I = 0.1 M (NaCl), t = (25.0 +/- 0.1) degrees of Celsius): adenine (pK_HL = 9.65 +/- 0.04, pK_H2L = 4.18 +/- 0.04), adenosine (pK_H2L = 3.59 +/- 0.05), cytosine (pK_H2L = 4.56 +/- 0.01), cytidine (pK_H2L = 4.16 +/- 0.02). In addition, thermodynamic parameters for bases were calculated. Acidobasic behavior of oligonucleotides ((CAC)3, A3C6, C3A3C3) was studied under the same experimental conditions by molecular absorption spectroscopy. pH-dependent spectral datasets were analyzed by means of advanced chemometric techniques (EFA, MCR-ALS) and the presence of hemiprotonated species concerning (C-C+) a non-canonical pair (i-motif) in titled oligonucleotides was proposed in order to explain experimental data obtained according to literature. |
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