Interaction of antioxidant flavonoids with tRNA: Intercalation or external binding and comparison with flavonoid-DNA adducts

dc.contributor.author	Kanakis, CD	en
dc.contributor.author	Tarantilis, PA	en
dc.contributor.author	Polissiou, MG	en
dc.contributor.author	Tajmir-Riahi, H-A	en
dc.date.accessioned	2014-06-06T06:47:19Z
dc.date.available	2014-06-06T06:47:19Z
dc.date.issued	2006	en
dc.identifier.issn	10445498	en
dc.identifier.uri	http://dx.doi.org/10.1089/dna.2006.25.116	en
dc.identifier.uri	http://62.217.125.90/xmlui/handle/123456789/3515
dc.subject.other	delphinidin	en
dc.subject.other	flavonoid	en
dc.subject.other	free radical	en
dc.subject.other	kaempferol	en
dc.subject.other	polyphenol	en
dc.subject.other	quercetin	en
dc.subject.other	transfer RNA	en
dc.subject.other	antioxidant activity	en
dc.subject.other	aqueous solution	en
dc.subject.other	article	en
dc.subject.other	binding affinity	en
dc.subject.other	complex formation	en
dc.subject.other	concentration response	en
dc.subject.other	DNA adduct	en
dc.subject.other	DNA damage	en
dc.subject.other	drug binding	en
dc.subject.other	infrared spectroscopy	en
dc.subject.other	priority journal	en
dc.subject.other	RNA binding	en
dc.subject.other	RNA conformation	en
dc.subject.other	RNA stability	en
dc.subject.other	RNA structure	en
dc.subject.other	ultraviolet spectroscopy	en
dc.subject.other	Anthocyanins	en
dc.subject.other	Antioxidants	en
dc.subject.other	DNA Adducts	en
dc.subject.other	Intercalating Agents	en
dc.subject.other	Kaempferols	en
dc.subject.other	Nucleic Acid Conformation	en
dc.subject.other	Quercetin	en
dc.subject.other	RNA, Transfer	en
dc.subject.other	Spectrophotometry, Ultraviolet	en
dc.subject.other	Spectroscopy, Fourier Transform Infrared	en
dc.title	Interaction of antioxidant flavonoids with tRNA: Intercalation or external binding and comparison with flavonoid-DNA adducts	en
heal.type	journalArticle	en
heal.identifier.primary	10.1089/dna.2006.25.116	en
heal.publicationDate	2006	en
heal.abstract	Antioxidants are essential to good health. Flavonoids are powerful antioxidants, and prevent DNA damage. The antioxidative protections are related to their binding modes to a DNA duplex and complexation with free radicals in vivo. Recently we reported the interaction of flavoeoids with DNA in vitro (Kanakis et al., J. Biomol. Struct. Dyn. 22, 719-724, 2005), where polyphenol different binding modes were discussed. The aim of this study was to examine the interaction of transfer RNA with quercetin (que), kaempferol (kae), and delphinidin (del) in aqueous solution at physiological conditions and to make a comparison with the corresponding pigment-DNA adducts. Constant tRNA concentration (6.25 mM) and various drug/RNA(phosphate) molar ratios of 1/48 to 1/8 were used. FTIR and UV-visible difference spectroscopic methods have been applied to determine the drug binding mode, the binding constants, and the effects of drug complexation on the stability and conformation of tRNA duplex. Both intercalative and external binding modes were observed. Structural analysis showed que, kae, and a del intercalate tRNA duplex with minor external binding to the major or minor groove and the backbone phosphate group with overall binding constants Kque = 4.80 × 104 M-1, Kkae = 4.65 × 104 M-1, and K del = 9.47 × 104 M-1. The stability of adduct formation is in the order of del > que > kae. A comparison with flavonoids-DNA adducts showed both intercalation and external bindings with the stability order Kque = 7.25 × 104 M-1, Kkae = 3.60 × 104 M-1, and K del = 1.66 × 104 M-1. Low flavonoid concentration induces helical stabilization, whereas high pigment content causes helix opening. A partial B-to A-DNA transition occurs at high drug concentration, while tRNA remains in the A-family structure. © Mary Ann Liebert, Inc.	en
heal.journalName	DNA and Cell Biology	en
dc.identifier.issue	2	en
dc.identifier.volume	25	en
dc.identifier.doi	10.1089/dna.2006.25.116	en
dc.identifier.spage	116	en
dc.identifier.epage	123	en