Copper complexes recognise DNA bases

Researchers are using copper complexes to look into the fine detail of the structure and folding pattern of nucleic acids. The transition metal technique could possibly be used in the future to help develop new chemotherapy compounds. 

Steven Rokita and colleagues at the University of Maryland, US, have made and studied a series of these copper complexes that specifically interact with and recognise the bases making up a nucleic acid. An affinity between a transition metal and a nucleobase is not in itself a rarity but Rokita has established the chemical and structural basis of at least some of these unique relationships. 

The benefits of copper over other transition metals is that only very mild conditions are necessary for binding reactions to occur, facilitating in vivo studies of DNA structure. Rokita’s copper complexes bind at the junction of the helical and coiled regions of nucleic acid. This structural motif is most often formed during DNA replication and is prevalent in dividing cells. Complexes that recognise and ultimately cleave this junction have the potential to show selective toxicity towards cells which are growing rapidly, such as those present in tumours. 

Learning precisely how metal complexes select their targets and promote reactions is very challenging. However, Rokita feels that ’knowledge gained from this area can be used in a rational approach to designing new materials with beneficial properties’.  

Suzanne Abbott