Cis- and trans-diamminedichloroplatinum(II) binding produces different tertiary structural changes on SV40 DNA

阅读量：

作者：

展开

摘要：

Cis-diamminedichloroplatinum(II), an active antineoplastic agent, and the inactive trans-isomer, bind to and alter the tertiary structure of supercoiled SV40 DNA. Cis-(NH 3) 2PtCl 2 is more effective in unwinding SV40 DNA than is the trans isomer and can unwind the DNA to the positively supercoiled form. This latter effect was not observed for trans-(NH 3) 2PtCl 2 at levels at least four times greater. Perhaps more significant, cis-(NH 3) 2PtCl 2 reduces the electrophoretic mobility of supercoiled DNA at very short reaction times, an effect that the binding of the trans isomer does not produce until the reaction has proceeded at least 50 times longer. These data suggest that the cis-isomer exhibits a mode of binding different than that of the trans isomer, a mode which is responsible for the more effectively unwinding of the DNA.

展开

关键词：

Simian virus 40 Cisplatin Guanine DNA, Superhelical DNA, Viral Electrophoresis, Agar Gel Nucleic Acid Conformation Stereoisomerism