Publication details
Thermal and thermodynamic properties of duplex DNA containing site-specific interstrand cross-link of antitumor cisplatin or its clinically ineffective trans isomer
| Authors | |
|---|---|
| Year of publication | 2001 |
| Type | Article in Periodical |
| Magazine / Source | Journal of Biological Chemistry |
| MU Faculty or unit | |
| Citation | |
| Field | Biophysics |
| Description | The effect of the site-specific interstrand cross-link formed by cisplatin or transplatin on the thermal stability and energetics of 20-base pairs DNA duplex is reported. The cross-linked or unplatinated 20-bp duplexes were investigated with the aid of differential scanning calorimetry, temperature-dependent UV absorption and circular dichroism. The cross-link of both platinum isomers increases the thermal stability of the modified duplexes by changing the molecularity of denaturation. The structural perturbation due to the interstrand cross-link of cisplatin increases entropy of the duplex. By contrast, the interstrand cross-link of transplatin is enthalpically almost neutral. These differences are consistent with distinct conformational distortions induced by the interstrand cross-links of the two isomers. It has been proposed that the results of the present work might be associated with distinctly different antitumor effects of these platinum compounds. |