Kimberley Callaghan

Postdoctoral Researcher

The University of Melbourne

Dr Kimberley Callaghan has a Ph.D. from the University of Cambridge, United Kingdom (2021). Working with Prof.Sir Christopher Dobson and Prof. Tuomas Knowles, she investigated the Thermodynamic Stability of Amyloid Fibrils. This research followed a biophysical chemistry career path from Kimberley’s honours between the Walter Eliza Hall Institute and University of Melbourne (2016). Working with A/Prof. Ethan Goddard-Borger and A/Prof. Jeff Babon, she studied Tryptophan C-Mannosylation. Kimberley returned to Australia and joined the Department of Chemical Engineering, University of Melbourne (2022) as a Research Associate in Synthetic DNA, to engineer a method for chemically joining DNA strands and investigate applications of this technology. Her prestigious and diverse research background, and expertise has enabled her to tackle multidisciplinary research challenges across science and engineering. Kimberley collaborates across projects within chemical engineering, nanotechnology and biochemistry, working to bring together researchers from a range of backgrounds and skills for a truly interdisciplinary approach. 

Engineering a simple approach to make synthetic DNA

Deoxyribonucleic acid (DNA) is best known for its role as an information storage molecule within biological cells, with the nucleotide sequence of DNA being translated into functional proteins. Synthetic DNA has found many uses, including in gene therapy within the clinic, as a conjugated tool compound for microscopy through DNA paint and even as a structural polymer through DNA origami.  The issue with synthetic DNA is in its commercial production which relies on solid-phase “protected” nucleotide extension reactions that generates a large amount of chemical waste (from removal of protecting groups) and also only produces single DNA strands up to 200-300 bases.  Thus, in order to make strands sufficiently useful in gene therapy the strands need to be chemically ligated (joined together). This can be costly and time consuming. This project aims to engineer an alternate method of DNA chemical ligation, which utilises imidazole activated nucleotides to chemically extend a DNA sequence. This chemistry removes the need for protecting groups, minimising the handling and waste associated with traditional ligation methods. The mild extension conditions are also compatible with aqueous conditions, offering a wide range of applications beyond DNA extension. Potential applications could include generating responsive DNA pendant polymers, incorporating nucleotides as a biocompatible linker between proteins, polymers or drug molecules or introducing DNA recognition motifs onto materials with desirable physicochemical properties.