What is the Difference Between Cisplatin and Transplatin?

Cisplatin and transplatin are structural isomers of each other, and they have different effects on DNA and gene expression. The key difference between the two is that cisplatin produces much more DNA adducts than transplatin. Cisplatin is widely used as an anticancer drug, while transplatin has no significant medicinal effect.

The differences in their interaction with DNA are as follows:

1. DNA adducts: Cisplatin forms mainly 1,2-intrastrand crosslinks (~80%) and rarely interstrand crosslinks (~1.5%). In contrast, transplatin forms monofunctional adducts and interstrand crosslinks at a higher frequency.
2. Platinum(II) atom binding: The platinum(II) atom in cisplatin preferentially binds to guanine-N7, followed by adenine-N7, adenine-N1, and cytosine-N3. Transplatin has a different mode of interaction with DNA.
3. Chlorine atom disposition: Cisplatin has two chlorine atoms on one side of the molecule, which allows it to bind to one more site on guanine compared to transplatin. Transplatin has one chlorine atom on each side of the molecule, making it less effective in binding to DNA.
4. Solubility: Cisplatin is not water-soluble, while transplatin is water-soluble to a considerable extent. When dissolved in water, transplatin undergoes hydrolysis.

These differences in DNA binding and solubility contribute to the therapeutic inactivity of transplatin compared to cisplatin.

Comparative Table: Cisplatin vs Transplatin

Cisplatin and transplatin are structural isomers of each other, with cisplatin being an effective chemotherapy drug and transplatin having no significant medicinal effect. Here is a table comparing the differences between cisplatin and transplatin:

In summary, cisplatin is an effective chemotherapy drug that prevents cell division by binding to DNA, while transplatin has no significant medicinal effect due to its reduced ability to bind to DNA.