CPL - Chalmers Publication Library
| Utbildning | Forskning | Styrkeområden | Om Chalmers | In English In English Ej inloggad.

Interactions of the Antiviral Quinoxaline Derivative 9-OH-B220 {2,3-dimethyl-6-(dimethylaminoethyl)-9-hydroxy-6H-indolo-[2,3-b] quinoxaline} with Duplex and Triplex forms of Synthetic DNA and RNA

U. Sehlstedt ; P. Aich ; J. Bergman ; H. Vallberg ; Bengt Nordén (Institutionen för fysikalisk kemi) ; A. Gräslund
Journal of Molecular Biology (0022-2836 ). Vol. 278 (1998), 1, p. 31-56.
[Artikel, refereegranskad vetenskaplig]

The binding of an antiviral quinoxaline derivative, 2,3-dimethyl-6-(dimethylaminoethyl)-9 -hydroxy-6H-indolo-[2,3-b]quinoxaline (9-OH-B220), to synthetic double and triple helical DNA (poly(dA).poly(dT) and poly(dA.)2poly(dT)) and RNA (poly(rA).poly(rU) and poly(rA) .2poly(rU)) has been characterized using flow linear dichroism (LD), circular dichroism (CD), fluorescence spectroscopy, and thermal denaturation. When either of the DNA structures or the RNA duplex serve as host polymers a strongly negative LD is displayed, consistent with intercalation of the chromophoric ring system between the base-pairs/triplets of the nucleic acid structures. Evidence for this geometry also includes weak induced CD signals and strong increments of the fluorescence emission intensities upon binding of the drug to each of these polymer structures. Ln agreement with intercalative binding, 9-OH-B220 is found to effectively enhance the thermal stability of both the double and triple helical states of DNA as well as the RNA duplex. Ln the case of poly(dA).2poly(dT), the drug provides an unusually large stabilization of its triple helical state; upon binding of 9-OH-B220 the tripler-to-duplex equilibrium is shifted towards higher temperature by 52.5 deg. C in a 10 mM sodium cacodylate buffer (pH 7.0) containing 100 mM NaCl and 1 mM EDTA. When triplex RNA serves as host structure, LD indicates that the average orientation angle between the drug chromophore plane and the helix axis of the triple helical RNA is only about 60 to 65 degrees. Moreover, the thermal stabilizing capability, as well as the fluorescence increment, CD inducing power and perturbations of the absorption envelope, of 9-OH-B220 in complex with the RNA tripler are all less pronounced than those observed for the complexes with DNA and duplex RNA. These features indicate binding of 9-OH-B220 in the wide and shallow minor groove of poly(rA).2poly(rU). Based on the present results, some implications for the applications of this low-toxic, antiviral and easily administered drug in an antigene strategy, as well as its potential use as an antiretroviral agent, are discussed

Nyckelord: nucleic acids, triple helix, intercalation, quinoxaline derivative, linear dichroism



Den här publikationen ingår i följande styrkeområden:

Läs mer om Chalmers styrkeområden  

Denna post skapades 2011-02-18. Senast ändrad 2011-07-08.
CPL Pubid: 136998

 

Läs direkt!


Länk till annan sajt (kan kräva inloggning)


Institutioner (Chalmers)

Institutionen för fysikalisk kemi (1900-2003)

Ämnesområden

Energi
Livsvetenskaper
Materialvetenskap
Nanovetenskap och nanoteknik
Fysikalisk kemi

Chalmers infrastruktur