Binding geometries of triple helix selective benzopyrido [4,3-b]indole ligands complexed with double- and triple-helical polynucleotides
✍ Scribed by Soeg K. Kim; Jian-Sheng Sun; Thérèse Garestier; Claude Hélène; C. H. Nguyen; E. Bisagni; Alison Rodger; Bengt Nordén
- Publisher
- Wiley (John Wiley & Sons)
- Year
- 1997
- Tongue
- English
- Weight
- 202 KB
- Volume
- 42
- Category
- Article
- ISSN
- 0006-3525
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✦ Synopsis
The binding modes of three benzopyrido [4,3-b]indole derivatives (and one benzo [f]pyrido [4-3b] [4,3-b]indole}, (II) 3-methoxy-11-[(3-amino)propylamino]-BePI, (III) 3-methoxy-7- [(3-diethylamino)propylamino]BgPI where BgPI Å {benzo[g]pyrido [4,3-b]in-dole}, and (IV) 3-methoxy-11-[(3-amino) [4-3b]quinoxaline}. The magnitudes of the reduced LD of the electronic transitions of the polynucleotide bases and of the bound ligands are generally very similar, suggesting an orientation of the plane of the ligands' fused-ring systems preferentially perpendicular to the helix axis. The LD results suggest that all of the ligands are intercalated for all three polynucleotides. The induced CD spectrum of the BePI chromophore in the (II-BePI)-poly[d(A-T)] 2 complex is almost a mirror image of that for the (I-BePI)-poly(dA)rpoly(dT) and (I-BePI)poly(dA)r2poly(dT) complexes, suggesting an antisymmetric orientation of the BePI moiety
quinoxaline derivative) with respect to double helical poly(dA)rpoly(dT) and poly[d(A-T)] 2 and triple-helical poly(dA)r2poly(dT) have been investigated using linear dichroism (LD) and CD: (I) 3-methoxy-11-amino-BePI where BePI