Researchers develop novel nanolitre screening technique
Determines protein stability and ligand‐binding affinity
This technique, pioneered by researchers from the UCL Department of Biochemical Engineering and the London Centre for Nanotechnology, in collaboration with Cambridge and Sussex Universities, is applicable to any free solution protein:drug interaction.
The technique applies microfluidics, using just nanolitres of sample – coupling protein stability and drug affinity analysis to microfluidic devices for sample preparation.
In a paper published in Protein Science journal, the researchers established a new nanolitre scale technique in micro-capillaries to measure intrinsic protein fluorescence and obtain accurate protein denaturation curves at equilibrium.
Free energies of protein unfolding were determined by this method for the first time and used to determine the affinity of the immunosuppressant rapamycin to the cellular immunophilin FKBP12 protein. The technique was also used to measure the interaction energy between rapamycin and the Phe99 residue of FKBP-12 from a double mutant cycle analysis. The method used combinations of two different protein mutations to study the molecular interactions within a given protein.
Until now, the modus operandi for protein analysis often meant either too much of the precious biological or compound materials was consumed in large sample volumes, or that chemical labelling with fluorescent tags was required to achieve measurements at submicrolitre volumes.
Dr David Sarphie, BNC’s chief executive, said: ‘This new method has vast implications and uses high throughput, low-cost platforms for drug discovery, protein engineering and protein formulation applications in the pharmaceutical industry.
‘Moreover, this technology marks a further development in the implementation of our corporate strategy to forge industry collaborations with leading academic and scientific organisations that possess the know-how to assess novel drug targets.’