title: Carbon nanotubes selective destabilization of duplex and triplex DNA and inducing B-A transition in solution.
abstract: Single-walled carbon nanotubes (SWNTs) have been considered as the leading candidate for nanodevice applications ranging from gene therapy and novel drug delivery to membrane separations. The miniaturization of DNA-nanotube devices for biological applications requires fully understanding DNA-nanotube interaction mechanism. We report here, for the first time, that DNA destabilization and conformational transition induced by SWNTs are sequence-dependent. Contrasting changes for SWNTs binding to poly[dGdC]:poly[dGdC] and poly[dAdT]:poly[dAdT] were observed. For GC homopolymer, DNA melting temperature was decreased 40 degrees C by SWNTs but no change for AT-DNA. SWNTs can induce B-A transition for GC-DNA but AT-DNA resisted the transition. Our circular dichroism, competitive binding assay and triplex destabilization studies provide direct evidence that SWNTs induce DNA B-A transition in solution and they bind to the DNA major groove with GC preference.
authors.affiliation: Division of Biological Inorganic Chemistry, Key Laboratory of Rare Earth Chemistry and Physics, Graduate School of the Chinese Academy of Sciences, Changchun Institute of Applied Chemistry, Chinese Academy of Sciences, Changchun, Jilin 130022, China.
authors.forename: Xi
authors.initials: X
authors.lastname: Li
authors.forename: Yinghua
authors.initials: Y
authors.lastname: Peng
authors.forename: Xiaogang
authors.initials: X
authors.lastname: Qu
mesh_terms: D001483:Base Sequence; D001667:Binding, Competitive; D002942:Circular Dichroism; D004247:DNA / Q000737:chemistry* / Q000648:ultrastructure; D044704:DNA, A-Form / Q000737:chemistry*; D018625:Microscopy, Atomic Force; D037742:Nanotubes, Carbon / Q000737:chemistry*; D009690:Nucleic Acid Conformation; D011131:Polyribonucleotides / Q000737:chemistry; D012996:Solutions; D013050:Spectrometry, Fluorescence
chemical_list: D044704:DNA, A-Form; D037742:Nanotubes, Carbon; D011131:Polyribonucleotides; D012996:Solutions; C051802:triplex DNA; D004247:DNA