biosensor, page-6

Tony: Great post.

Interesting to read this comment in the PYC annual report:

Professor Kirill Alexandrov said: “.......by giving Phylogica access to our novel technologies for recombinant peptide production and analysis we expect to dramatically shorten development time for novel diagnostic applications.”

and then to read the overview of Alexandrov's February lecture for the 'HZI Colloquium' at the Helmholtz Centre for Infection Research in Braunschweig:

"Synthetic sensing and signal transduction cascades based on artificial autoinhibited proteases"

The central tenet of the emerging field of Synthetic Biology is that biological components can be refined into a toolkit of plug-and-play building blocks. The experimental evidence supporting this idea has so far been limited to relatively slow synthetic gene expression circuits. Real-time events in biological process are mediated by protein-based signaling circuits that can operate up to the millisecond scale. Ability to design protein-based signaling circuits would in principle enable us to design of analytical and diagnostic tests for any analyte. To create orthogonal toolbox of protein-based signal detectors and amplifiers we combined structure-based engineering and directed evolution of proteins. This approach allowed us to create artificial auto-inhibited proteases with non-overlapping substrate specificities. These molecules are inactive in their ground state but are activated by changes in their structure that dislodge the inhibitor from the active site. Incorporation of a ligand-binding domain into such basic signaling unit allowed us to create an allostercally regulated receptor protease. We demonstrate that a complete signal detection and amplification cascade can be assembled from such synthetic protein units. Such cascades are easily connectable to existing electronic detectors through engineered artificial zymogenes. Using this approach we created biosensors of cancer markers such as prostate specific antigen and several matrix metalloproteinases as well as proteases of blood coagulation cascade. We demonstrate that the cascades operate effectively in biological fluids and can be used for building POC applications.
............
SoT