Tetramolecular G-quadruplexes result from the association of four guanine-rich strands. Modification of the backbone strand or the guanine bases of the oligonucleotide may improve stability or introduce new functionalities. In this regard, the 8 position of a guanosine is particularly suitable for introduction of modifications since as it is positioned in the groove of the quadruplex structure. Modifications at this position should not interfere with structural assembly as would changes atWatsoneCrick and Hoogsteen sites. In this study, we investigated the effect of an 8-methyl-20-deoxyguanosine residue (M) on the structure and stability of tetramolecular parallel G-quadruplexes. In some cases, the presence of this residue resulted in the formation of unusual quadruplex structures containing all-syn tetrads. Furthermore, the modified nucleoside M at the 50-end of the sequence accelerated quadruplex formation by 15-fold or more relative to the unmodified oligonucleotide, which makes this nucleobase an attractive replacement for guanine in the context of tetramolecular parallel quadruplexes.
Effects of 8-methylguanine on structure, stability and kinetics of formation of tetramolecular quadruplexes / Tran, P. L. T.; Virgilio, Antonella; Esposito, Veronica; Citarella, Giuseppe; Mergny, J. L.; Galeone, Aldo. - In: BIOCHIMIE. - ISSN 0300-9084. - 93:3(2011), pp. 399-408. [10.1016/j.biochi.2010.10.011]
Effects of 8-methylguanine on structure, stability and kinetics of formation of tetramolecular quadruplexes
VIRGILIO, ANTONELLA;ESPOSITO, VERONICA;CITARELLA, GIUSEPPE;GALEONE, ALDO
2011
Abstract
Tetramolecular G-quadruplexes result from the association of four guanine-rich strands. Modification of the backbone strand or the guanine bases of the oligonucleotide may improve stability or introduce new functionalities. In this regard, the 8 position of a guanosine is particularly suitable for introduction of modifications since as it is positioned in the groove of the quadruplex structure. Modifications at this position should not interfere with structural assembly as would changes atWatsoneCrick and Hoogsteen sites. In this study, we investigated the effect of an 8-methyl-20-deoxyguanosine residue (M) on the structure and stability of tetramolecular parallel G-quadruplexes. In some cases, the presence of this residue resulted in the formation of unusual quadruplex structures containing all-syn tetrads. Furthermore, the modified nucleoside M at the 50-end of the sequence accelerated quadruplex formation by 15-fold or more relative to the unmodified oligonucleotide, which makes this nucleobase an attractive replacement for guanine in the context of tetramolecular parallel quadruplexes.I documenti in IRIS sono protetti da copyright e tutti i diritti sono riservati, salvo diversa indicazione.
