Examination of the effect of the annealing cation on higher order structures containing guanine or isoguanine repeats.
Examination of the effect of the annealing cation on higher order structures containing guanine or isoguanine repeats.
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DOI：
10.1002/chem.200901047
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发表时间：
2009-10-26
影响因子：
4.3
通讯作者：
Brodbelt, Jennifer S.
中科院分区：
文献类型：
--
作者：
Pierce, Sarah E.;Wang, Junmei;Jayawickramarajah, Janarthanan;Hamilton, Andrew D.;Brodbelt, Jennifer S.
Isoguanine (2-oxo-6-amino-guanine), a natural but non-standard base, exhibits unique self-association properties compared to its isomer, guanine, and results in formation of different higher order DNA structures. In this work, the higher order structures formed by oligonucleotides containing guanine repeats or isoguanine repeats after annealing in solutions containing various cations are evaluated by electrospray ionization mass spectrometry (ESI-MS) and circular dichroism (CD) spectroscopy. The guanine-containing strand (G9) consistently formed quadruplexes upon annealing, whereas the isoguanine strand (Ig9) formed both pentaplexes and quadruplexes depending on the annealing cation. Quadruplex formation with G9 showed some dependence on the identity of the cation present during annealing with high relative quadruplex formation detected with six of ten cations. Analogous annealing experiments with Ig9 resulted in complex formation with all ten cations, and the majority of the resulting complexes were pentaplexes. CD results indicated most of the original complexes survived the desalting process necessary for ESI-MS analysis. In addition, several complexes, especially the pentaplexes, were found to be capable of cation exchange with ammonium ions. Ab initio calculations were conducted for isoguanine tetrads and pentads coordinated with all ten cations to predict the most energetically stable structures of the complexes in the gas phase. The observed preference of forming quadruplexes versus pentaplexes as a function of the coordinated cation can be interpreted by the calculated reaction energies of both the tetrads and pentads in combination with the distortion energies of tetrads.
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影响因子：
2.3
作者：
Aggerholm, T;Nanita, SC;Cooks, RG
通讯作者：
Cooks, RG
影响因子：
1.8
作者：
Baker, Erin Shammel;Bernstein, Summer L.;Bowers, Michael T.
通讯作者：
Bowers, Michael T.
影响因子：
15
作者：
Davis, JT;Tirumala, SK;Marlow, AL
通讯作者：
Marlow, AL
影响因子：
3.3
作者：
Gu, JD;Leszczynski, J
通讯作者：
Leszczynski, J
DOI：
10.1023/a:1011120723100
发表时间：
2001-06-01
影响因子：
2.3
作者：
Lee, SC;Lamb, JD;Davis, JT
通讯作者：
Davis, JT