The Problem at Hand
The COVID-19 pandemic has highlighted that we need better ways to accurately and quickly diagnose infectious diseases.
Lateral flow assays or rapid antigen tests (RATs) were a critical part of our response to the pandemic.
However, these need to be redeveloped with a new antibody every time a new disease emerges.
Current methods of antibody development require innoculation of animals, which is slow and raises ethical issues.
Our Solution
Nanobodies are a promising alternative to regular antibodies for use in RATs and other biomedical contexts.
These can be made in recombinant microbial systems, bypassing the need for animal inoculation.
In addition nanobodies offer new opportunities such as in vitro evolution (e.g. DNA shuffling) to develop new antigen specificities.
Our Project
We used two variants of GFP as a model system to investigate DNA shuffling of nanobodies to determine if their binding specificity could be evolved from superfolder GFP (sfGFP) to free use GFP (fuGFP).
GFPs were fused to cellulose binding domains (CBDs) and immobilised on paper and screened against E. coli cells displaying libraries of evolved nanobodies fused to Neae-intimin, an outer membrane protein.
We believe this model system is foundational and will lead to numerous applications for nanobodies across diverse areas. To expand the possibilities of this system we tested multiple CBDs and developed new green, blue, and yellow variants of fuGFP with and without CBD tags.