The effect of ionic strength on melting of DNA modified by platinum(II) complexes
Jazyk angličtina Země Nizozemsko Médium print
Typ dokumentu časopisecké články, práce podpořená grantem
PubMed
8679924
DOI
10.1016/0301-4622(96)00010-5
PII: 0301462296000105
Knihovny.cz E-zdroje
- MeSH
- antitumorózní látky chemie farmakologie MeSH
- chemické jevy MeSH
- chemie fyzikální MeSH
- denaturace nukleových kyselin účinky léků MeSH
- DNA chemie účinky léků MeSH
- molekulární sekvence - údaje MeSH
- organoplatinové sloučeniny chemie farmakologie MeSH
- osmolární koncentrace MeSH
- sekvence nukleotidů MeSH
- skot MeSH
- zvířata MeSH
- Check Tag
- skot MeSH
- zvířata MeSH
- Publikační typ
- časopisecké články MeSH
- práce podpořená grantem MeSH
- Názvy látek
- antitumorózní látky MeSH
- DNA MeSH
- organoplatinové sloučeniny MeSH
Thermal denaturation of calf thymus DNA modified by antitumor cis-diamminedichloroplatinum(II) (cis-DDP) and by two related Pt(II) compounds which had been shown to be clinically ineffective, viz. trans-diamminedichloroplatinum(II) (trans-DDP) or monodentate diethylenetriaminechloroplatinum(II) chloride [[Pt(dien)Cl)]Cl], was studied by monitoring changes of absorbance at 260 nm. The melting of DNA platinated to different levels was investigated in neutral media containing varying concentrations of Na+. It has been shown that the ionic strength has a strong influence on the character and magnitude of changes in the melting temperature of DNA (Tm) induced by the platination. The modification of DNA by either platinum complex used in this work results in an increase of Tm if DNA melting is measured in media containing low Na+ concentrations (ca. 1 mM). This effect is reversed at higher Na+ concentrations. The concentration of Na+ at which this reversal occurs is, however, markedly lower for DNA modified by cis-DDP than for DNA modified by the other two platinum complexes. These results have been interpreted to mean that at least three factors affect the thermal stability of DNA modified by the platinum(II) complexes: stabilization effects of the positive charge on the platinum moiety and of interstand cross-links, and a destabilization effect of conformational distortions in DNA. Thus, in order to compare and interpret the melting behavior of DNA modified by different compounds, a great attention has to be paid to the composition of the medium in which the melting experiments are carried out.
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