title: Molecular-level helical stack of a nucleotide-appended oligo(p-phenylenevinylene) directed by supramolecular self-assembly with a complementary oligonucleotide as a template.
abstract: The nucleotide-appended oligo(p-phenylenevinylene), {bis[2,5-bis(2-methoxyethoxy)-1,4-phenylene]bis(2,1-ethenediyl-1,4-phenylenemethylene)}bis(2'-deoxy-3'-thymidylic acid) (8), has been synthesized, and self-assembly of the single-component 8 and binary self-assembly of 8 with a complementary single-stranded 20-meric oligodeoxyadenylic acid (9) have been examined in aqueous solutions. Atomic force microscopy (AFM), UV-visible (UV-vis), and circular dichroism (CD) measurements revealed that right-handed helical stacks with 6.4- and 5.1-nm diameters self-assemble from the binary components of 8 and 9 as a template depending on the residual stoichiometry of the two components (thymine (T):adenine (A) = 1:1 and T:A = 2:1, respectively). The concentration of 9 was found to strongly influence the CD spectra of 8 in aqueous solutions. Consequently, we concluded that the one side of the thymine moieties in the stacked assemblies of 8 complexes with a single chain of 9. Complementary T-A base pairs thus formed and induced helical stack of the oligo(p-phenylenevinylene)s in the binary self-assembly. In contrast, self-assembly of the single-component 8 and binary self-assembly of 8 with the noncomplementary 20-meric oligothymidylic acid (10) produced no remarkable formation of fibrous structures like helical stacks.
authors.affiliation: Nanoarchitectonics Research Center, National Institute of Advanced Industrial Science and Technology, Tsukuba Central 5, Tsukuba, Ibaraki 305-8565, Japan.
authors.forename: Rika
authors.initials: R
authors.lastname: Iwaura
authors.forename: Freek J M
authors.initials: FJ
authors.lastname: Hoeben
authors.forename: Mitsutoshi
authors.initials: M
authors.lastname: Masuda
authors.forename: Albertus P H J
authors.initials: AP
authors.lastname: Schenning
authors.forename: E W
authors.initials: EW
authors.lastname: Meijer
authors.forename: Toshimi
authors.initials: T
authors.lastname: Shimizu
mesh_terms: D002942:Circular Dichroism; D007700:Kinetics; D018625:Microscopy, Atomic Force; D008958:Models, Molecular; D009841:Oligonucleotides / Q000138:chemical synthesis* / Q000737:chemistry; D011145:Polyvinyls / Q000138:chemical synthesis* / Q000737:chemistry; D013056:Spectrophotometry, Ultraviolet
chemical_list: D009841:Oligonucleotides; D011145:Polyvinyls; C470024:poly(4-phenylenevinylene)