Development of single-molecule antigen sensors for diagnostics

Molecular Horizons Seminar - Dr Lisanne Spenkelink
-
-
-
Wollongong Campus
32-G01
The detection of disease biomarkers is important in all aspects of modern medicine. Detection of proteins is particularly important because, in contrast to genetic markers, the presence of proteins is often connected with disease phenotypes directly. In collaboration with Quantum-Si, a US-based single-molecule protein-sequencing company, we have worked on the development of rapidly-customisable biosensors for the detection of low-abundant biomarkers.
Our strategy is based on nanobodies: small (15 kDa) single-domain antibodies that can be easily expressed, are highly stable, and can be evolved easily for protein engineering. I will discuss how we adapted and optimised these nanobodies into two classes of fluorescent antigen sensors: Quenchbodies and Oligobodies. Quenchbodies are easy to use, fast, and easy to produce and adapt. Using Interleukin-6 as an example, we show that our Quenchbody scaffold can be rapidly evolved for the detection of any protein. Oligobodies are particularly powerful for the detection of very-low-abundant proteins. Using single-molecule visualisation of Oligobodies, we have detected antigens at concentrations as low as 7 pM (~0.1 pg/ml).
We believe our designs provide valuable platforms for developing biosensors for diverse protein targets, with applications in research, diagnostics, and environmental monitoring.