ISSN:
1432-1327
Keywords:
Parallel-stranded DNA Antigene Platinum Triplex Transplatin
Source:
Springer Online Journal Archives 1860-2000
Topics:
Biology
,
Chemistry and Pharmacology
Notes:
Abstract. The oligonucleotides 5′-d(TTTTCTTTTG) and 5′-d(AAAAGAAAAG) were cross-linked with a trans-[Pt(NH3)2]2+ entity via the N7 positions of the 3′-end guanine bases to give parallel-stranded (ps) DNA. At pH 4.2, CD and NMR spectroscopy indicate the presence of Hoogsteen base pairing. In addition, temperature-dependent UV spectroscopy shows an increase in melting temperature for the platinated duplex (35 °C) as compared to the non-platinated, antiparallel-stranded duplex formed from the same oligonucleotides (21 °C). A monomer-dimer equilibrium for the platinated 20mer is revealed by gel electrophoresis. At pH 4.2, addition of a third strand of composition 5′-d(AGCTTTTCTTTTAG) to the ps duplex leads to the formation of a triple helix with two distinct melting points at 38 °C (platinum cross-linked Hoogsteen part) and 21 °C (Watson-Crick part), respectively.
Type of Medium:
Electronic Resource
URL:
http://dx.doi.org/10.1007/s007750000143
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