​Scientists from the University of Strathclyde, UCB Pharma and CLF used 2D-IR spectroscopy to quantify changes in the secondary structure of the multifunctional calcium-binding messenger protein Calmodulin (CaM).​

Making use of the CLF's Ultra system, the team measured subtle protein conformational changes in solution - as a function of temperature and Calcium (Ca2+) concentration - using 2D-IR spectroscopy in combination with multivariate analysis. This work opens up the possibility to observe structural changes of proteins in solution in real time via a label-free method.

CLF's Ultra system, housed within the Research Complex at Harwell, is one of the world's most sensitive 2D-IR spectrometers and is used to investigate dynamics of complex biological systems such as the protein Calmodulin studied in this experiment.  

By measuring the thermal stability and Ca2+ - binding transition of human CaM with IR absorption and 2D-IR spectroscopy, the team have proved that 2D-IR can be used to reliably quantify relative changes in secondary structure elements in proteins by measuring subtle changes in the 2D-IR spectra of the amide I IR absorption band. 

Not only can ultrafast 2D-IR spectroscopy of unlabelled proteins help scientists paint a broader picture of conformational change but it can also help create a platform for spatially targeted studies.

The research was supported by academic access to CLF and the full publication is available to view in the journal Analytical Chemistry.