Platination of the (T2G4)4 Telomeric Sequence: A Structural and Cross-Linking Study
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- 作者：Sophie Redon ; Sophie Bombard ; Miguel-Angel Elizondo-Riojas ; and Jean-Claude Chottard
- 刊名：Biochemistry
- 出版年：2001
- 出版时间：July 24, 2001
- 年：2001
- 卷：40
- 期：29
- 页码：8463 - 8470
- 全文大小：429K
- 年卷期：v.40,no.29(July 24, 2001)
- ISSN：1520-4995
文摘
The telomeric sequence (T2G4)4 was platinated in aqueous solutions containing 50 mM LiClO4,NaClO4, or KClO4. The identification of the guanines which reacted with [Pt(NH3)3(H2O)]2+ revealedthat the same type of folding exists in the presence of the three cations and that the latter determine therelative stabilities of the G-quadruplex structures in the order K+ > Na+ 
Li+. The tri-ammine complexyielded ca. 40-90% of adducts, mono- and poly-platinated, bound to 4 guanines out of the 16 guaninesin the sequence, in the decreasing amounts G9 > G15 G3 > G21. The formation of these adducts wasinterpreted with a G-quadruplex structure obtained by restrained molecular dynamics (rMD) simulationswhich confirms the schematic model proposed by Williamson et al. [(1989) Cell 59, 871-880]. Thebifunctional complexes cis- and trans-[Pt(NH3)2(H2O)2]2+ also first reacted with G9 and G15 and gavecross-linked adducts between two guanines, which did not exceed 5% each of the products formed. Boththe cis and trans isomers formed a G3-G15 platinum chelate, and the second also formed bis-chelates atboth ends of the G-quadruplex structure: G3-G15/G9-G21 and G3-G15/G9-G24. The rMD simulationsshowed that the cross-linking reactions by the trans complex can occur without disturbing the stacking ofthe three G-quartets.
Li+. The tri-ammine complexyielded ca. 40-90% of adducts, mono- and poly-platinated, bound to 4 guanines out of the 16 guaninesin the sequence, in the decreasing amounts G9 > G15 G3 > G21. The formation of these adducts wasinterpreted with a G-quadruplex structure obtained by restrained molecular dynamics (rMD) simulationswhich confirms the schematic model proposed by Williamson et al. [(1989) Cell 59, 871-880]. Thebifunctional complexes cis- and trans-[Pt(NH3)2(H2O)2]2+ also first reacted with G9 and G15 and gavecross-linked adducts between two guanines, which did not exceed 5% each of the products formed. Boththe cis and trans isomers formed a G3-G15 platinum chelate, and the second also formed bis-chelates atboth ends of the G-quadruplex structure: G3-G15/G9-G21 and G3-G15/G9-G24. The rMD simulationsshowed that the cross-linking reactions by the trans complex can occur without disturbing the stacking ofthe three G-quartets.