New Antibiotics Could Come from a DNA Binding Compound

photo: bacteria

The DNA binding compound targets
drug-resistant bacteria; © SXC

The DNA binding properties of the compound were first discovered in the Department of Chemistry at the University of Warwick by Professor Mike Hannon and Professor Alison Rodger. However, the strength of its antibiotic powers has now made it a compound of high interest for University of Warwick researchers working on the development of novel antibiotics.

The compound [Fe2L3]4+ is an iron triple helicate with three organic strands wrapped around two iron centres to give a helix which looks cylindrical in shape and neatly fits within the major groove of a DNA helix. It is about the same size as the parts of a protein that recognise and bind with particular sequences of DNA. The high positive charge of the compound enhances its ability to bind to DNA which is negatively charged.

When the iron-helicate binds to the major groove of DNA it coils the DNA so that it is no longer available to bind to anything else and is not able to drive biological or chemical processes.

Research at the University of Warwick, led by Dr Adair Richards and Dr Albert Bolhuis, has found that the [Fe2L3]4+ does have a powerful effect on bacteria. When introduced to two test bacteria Bacillus subtilis and E. coli they found that it quickly bound to the bacteria's DNA and killed virtually every cell within two minutes of being introduced - though the concentration required for this is high.

The researchers will next try and understand how and why the compound can cross the bacteria cell wall and membranes. They plan to test a wide range of compounds to look for relatives of the iron helicate that have the same mechanism for action in collaboration with researchers around the world.; Source: University of Warwick