Fu Y.,Key Laboratory for Green Chemical Technology MOE |
Wang X.,Key Laboratory for Green Chemical Technology MOE |
Zhang J.,Key Laboratory for Green Chemical Technology MOE |
Xiao Y.,Key Laboratory of Systems Bioengineering MOE |
And 2 more authors.
Biomacromolecules | Year: 2011
Spermine-induced orderly assembling properties of G-/C-rich oligonucleotides are investigated in dilute and crowding conditions. The first time we report that the parallel G-quadruplexes is preferential to condense into anisotropic microaggregates in the presence of spermine, whereas the hybrid-type and the antiparallel G-quadruplexes have no significant interactions with spermine; and spermine can induce the condensation of i-motif C-rich oligonucleotides other than the random coiled C-rich strands. Moreover, the condensation of C-rich oligonucleotides can be reversibly regulated by pH and temperature. G-/C-rich oligonucleotides exhibit the cholesteric liquid crystalline phase at low strand concentration in the presence of spermine under crowding conditions. The results illuminate that the parallel G-quadruplex and i-motifs are probably necessity conformations for G-/C-rich oligonucleotides that involved in the regulation of chromosome organization in living cells. © 2011 American Chemical Society.