title: Binding studies of terbutaline sulfate to calf thymus DNA using multispectroscopic and molecular docking techniques.
abstract: The interaction of terbutaline sulfate (TS) with calf thymus DNA (ctDNA) were investigated by fluorescence quenching, UV-vis absorption, viscosity measurements, ionic strength effect, DNA melting experiments and molecular docking. The binding constants (Ka) of TS to ctDNA were determined as 4.92×10(4), 1.26×10(4) and 1.16×10(4) L mol(-1) at 17, 27 and 37 °C, respectively. Stern-Volmer plots suggested that the quenching of fluorescence of TS by ctDNA was a static quenching. The absorption spectra of TS with ctDNA revealed a slight blue shift and hyperchromic effect. The relative viscosity ctDNA was hardly changed by TS, and melting temperature varied slightly. For the system of TS-ctDNA, the intensity of fluorescence decreased with the increase of ionic strength. Also, the Ka for TS-double stranded DNA (dsDNA) was clearly weaker than that for TS-single stranded DNA (ssDNA). All these results revealed that the binding mode of TS with ctDNA should be groove binding. The enthalpy change and entropy change suggested that van der Waals force or hydrogen bonds was a main binding force between TS and ctDNA. Furthermore, the quantum yield of TS was measured by comparing with the standard solution. Based on the Förster energy transference theory (FRET), the binding distance between the acceptor and donor was calculated. Molecular docking showed that TS was a minor groove binder of ctDNA and preferentially bound to A-T rich regions.
authors.affiliation: College of Chemistry, Changchun Normal University, Changchun 130032, China. Electronic address: sy_bi@sina.com.
authors.forename: Shuyun
authors.initials: S
authors.lastname: Bi
authors.affiliation: College of Chemistry, Changchun Normal University, Changchun 130032, China.
authors.forename: Tingting
authors.initials: T
authors.lastname: Zhao
authors.affiliation: College of Chemistry, Changchun Normal University, Changchun 130032, China.
authors.forename: Yu
authors.initials: Y
authors.lastname: Wang
authors.affiliation: College of Chemistry, Changchun Normal University, Changchun 130032, China.
authors.forename: Huifeng
authors.initials: H
authors.lastname: Zhou
authors.affiliation: Technology Center of Inspection and Quarantine, Jilin Entry-Exit Inspection and Quarantine Bureau, Changchun 130062, China.
authors.forename: Bo
authors.initials: B
authors.lastname: Pang
authors.affiliation: Technology Center of Inspection and Quarantine, Jilin Entry-Exit Inspection and Quarantine Bureau, Changchun 130062, China.
authors.forename: Tingting
authors.initials: T
authors.lastname: Gu
mesh_terms: D000818:Animals; D001993:Bronchodilator Agents / Q000378:metabolism*; D002417:Cattle; D004247:DNA / Q000378:metabolism*; D062105:Molecular Docking Simulation; D009994:Osmolar Concentration; D011485:Protein Binding; D013050:Spectrometry, Fluorescence; D013056:Spectrophotometry, Ultraviolet; D013726:Terbutaline / Q000378:metabolism*; D013816:Thermodynamics; D014783:Viscosity
chemical_list: D001993:Bronchodilator Agents; D004247:DNA; C427203:calf thymus DNA; D013726:Terbutaline
keywords: Binding mode; DNA; Fluorescence quenching; Molecular docking; Terbutaline sulfate (TS)