Poster Presentation 11th Annual Conference of the International Chemical Biology Society 2022

A PLATFORM FOR ENGINEERING CHEMICALLY INDUCED DIMERISATION SYSTEMS AND THEIR USE IN PROTEIN BIOSENSORS. (#124)

Maria Micaela Fiorito 1 2 3 , Zhenling Cui 1 2 3 , Zhong Guo 1 2 3 , Patricia Walden 2 3 , Kirill Alexandrov 1 2 3 4 5
  1. ARC Centre of Excellence in Synthetic Biology, Australia
  2. Centre for Agriculture and the Bioeconomy, Queensland University of Technology, Brisbane, Australia
  3. School of Biology and Environmental Science, Queensland University of Technology, Brisbane, Australia
  4. CSIRO-QUT Synthetic Biology Alliance, Brisbane, Australia
  5. Centre for Genomics and Personalised Health, Queensland University of Technology, Brisbane, Australia

Protein biosensors are powerful systems that can detect specific analytes present in complex mixtures and solutions. These biosensors have great potential to replace expensive analytic methods and reduce the requirement for costly personnel and complicated tests due to the creation of low-cost point-of-care devices.

Protein biosensors are composed of receptors and reporters. The binding of a ligand to the receptor (input) results in signal transmission to the reporter and processing of its activity (output). Although many studies demonstrated remarkable progress in the development of novel protein biosensors, they also identified two significant limitations that restrict their use in diagnostics, analytics, and industrial processes:

  • Most laboratory-scale biosensors have a significant time delay, making them unsuitable for delivering rapid test results.
  • No platform is available for developing an appropriate receptor domain susceptible to any analyte of choice.

To address these problems, we designed a platform for engineering chemically induced dimerisation systems, utilising phage display, a powerful and innovative platform for displaying polypeptides on the surface of filamentous phages. The phage library is based on the Fibronectin Type III (FN3con) domain.

This library was then utilised to obtain proteins that interact with any small molecule of interest, such as environmental contaminants or drugs. The procedure begins with immobilising the small molecule on a solid surface, followed by exposure to the phage library. Once the small molecule:protein complex is developed, it is used to select a second binder that recognises the initial molecule:protein complex.

Once the desired ternary complex is discovered, it can be used to create highly sensitive and specific biosensors for a range of analytes. The receptors will be linked to various enzymatic reporters, able to transmit the output signal rapidly and efficiently.

In conclusion, the developed system has the potential to serve as a platform to identify receptor systems capable of dimerising in the presence of any small molecule of interest, having the advantage of being fused with any reporter domain.