title: Structural isomers and binding sites of guanine-rich quadruplexes investigated by induced circular dichroism of thionin: loops and tails.
abstract: Induced circular dichroism has been used to study the binding of thionin molecule to twelve guanine-rich quadruplexes. Substituting the base in the loops and varying the length of the tails could substantial change the induced circular dichroism spectra, which allow us to distinguish structural isomers and to determine the binding sites of quadruplexes. Our results show that external stacking on the end surface of the G-quartet associated with electrostatic interaction with the loops or tails is the major binding mode of thionin with these G-quadruplexes.
authors.affiliation: Institute of Atomic and Molecular Sciences, Academia Sinica, P.O. Box 23-166, Taipei, 106, Taiwan. tcchang@po.iams.sinica.edu.tw
authors.forename: Jin-Yi
authors.initials: JY
authors.lastname: Wu
authors.forename: Ccheng-Chung
authors.initials: CC
authors.lastname: Chang
authors.forename: Cheng-Sheng
authors.initials: CS
authors.lastname: Yan
authors.forename: Kuan-Yu
authors.initials: KY
authors.lastname: Chen
authors.forename: I-Chun
authors.initials: IC
authors.lastname: Kuo
authors.forename: Chung-Yuan
authors.initials: CY
authors.lastname: Mou
authors.forename: Ta-Chau
authors.initials: TC
authors.lastname: Chang
mesh_terms: D001483:Base Sequence; D001665:Binding Sites; D002942:Circular Dichroism; D004396:Coloring Agents / Q000378:metabolism*; D006147:Guanine / Q000032:analysis*; D009841:Oligonucleotides / Q000737:chemistry*; D013056:Spectrophotometry, Ultraviolet; D055672:Static Electricity; D013237:Stereoisomerism
chemical_list: D004396:Coloring Agents; D009841:Oligonucleotides; D006147:Guanine