Poster Presentation The 48th Lorne Conference on Protein Structure and Function 2023

PROTEIN BIOSENSORS FOR DETECTING SMOKE EXPOSURE OF GRAPES (#325)

Maria M Fiorito 1 2 3 , Zhenling Cui 1 2 3 , Patricia Walden 1 2 3 , Zhong Guo 1 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 environmental contaminants deposited in wine grapes that affect wine quality.

Smoke exposure of grapes during ripening leads to the uptake of smoke phenolic compounds such as cresol, syringol and other related compounds. In the presence of sugars and acids, the phenolic glycosides do not induce an easily perceivable taste sensation in grape juice, and therefore their presence cannot be detected. In ageing, some glycosides are hydrolysed, creating an unpleasant ashy, medicinal aftertaste, which is referred to as smoke taint. Smoke taint is a serious quality defect of wine. Finding proteins that could dimerise the compound that causes this defect, smoked taint phenolic glycosides, could help growers reduce the financial and environmental impact on massive amounts of grapes not suitable for use.