Molecular and Nanoscale Physics

Current Research Interests

Single molecule force spectroscopy as a tool to measure mechanical properties

Single molecule manipulation

One of the most exciting developments in the field of biological physics in recent years is the ability to manipulate single molecules and probe their properties and function. Single molecule force spectroscopy has become a powerful tool to explore the response of biological molecules, including proteins, DNA, RNA and their complexes, to the application of an applied force. The force versus extension response of molecules can provide valuable insight into its mechanical stability, as well as details of the underlying energy landscape.

 

Tuning protein mechanics through an ionic cluster graft from an extremophilic protein

Life in extreme environments

Extremophiles are organisms which survive and thrive in extreme environments. The proteins from extremophilic single-celled organisms  are structurally stable and functionally active under extreme physical and chemical conditions. We are using single molecule force spectroscopy to mechanically manipulate proteins from extremophilic organisms to gain information about their stability, flexibility and underlying energy landscapes.

 

Examining hydrogen bonded networks in a cryoprotectant solution

Physics of Cryopreservation

Cryoprotectant molecules are widely used in basic molecular research through to industrial and biomedical applications. The molecular mechanisms by which cryoprotectants stabilise and protect molecules and cells, along with suppressing the formation of ice, are incompletely understood. To gain greater insight, we complete experiments to determine the structure of cryoprotectant solutions at low temperatures. Our investigations combine neutron diffraction experiments with isotopic substitution and computational modelling to determine the atomistic level structure of the  mixtures. We examine the local structure of the system including the water structure.

 

Neutron diffraction and computational modelling provide access to structural information on biological molecule association in solution

Molecular Self-assembly

Recent studies suggest that hydrophilic interactions play an important role in controlling self-assembly in biological processes. To explore the effect of temperature on this interaction we use neutron diffraction coupled with isotopic substitution and computational modelling to examine the structure of biological molecules in solution. These studies are important because they highlight the necessity to consider hydrophilic interactions in the self-assembly and association of biological systems, and not just the more traditional hydrophobic interaction.

Polypeptide chain aggregation

- Structure and hydration of amino acids in aqueous solution

- Structural examination of polypeptide chains

- Biophysical characterisation of polypeptide chain stabilty

- Kinetics of aggregation of polypeptide chains