Design of polarity-dependent immunosensors based on the structural analysis of engineered antibodies Journal Article


Authors: Islam, J.; Conroy, P.; Fercher, C.; Kim, M.; Yaari, Z.; Jones, M.; Bell, T. D. M.; Caradoc-Davies, T.; Law, R.; Whisstock, J.; Heller, D.; Mahler, S.; Corrie, S.
Article Title: Design of polarity-dependent immunosensors based on the structural analysis of engineered antibodies
Abstract: “Reagentless” immunosensors are emerging to address the challenge of practical and sensitive detection of important biomarkers in real biological samples without the need for multistep assays and user intervention, with applications ranging from research tools to point-of-care diagnostics. Selective target binding to an affinity reagent is detected and reported in one step without the need for washing or additional reporters. In this study, we used a structure-guided approach to identify a mutation site in an antibody fragment for the polarity-dependent fluorophore, Anap, such that upon binding of the protein target cardiac troponin I, the Anap-labeled antibody would produce a detectable and dose-dependent shift in emission wavelength. We observed a significant emission wavelength shift of the Anap-labeled anti-cTnI mutant, with a blue shift of up to 37 nm, upon binding to the cTnI protein. Key differences in the resulting emission spectra between target peptides in comparison to whole proteins were also found; however, the affinity and binding characteristics remained unaffected when compared to the wild-type antibody. We also highlighted the potential flexibility of the approach by incorporating a near-infrared dye, IRDye800CW, into the same mutation site, which also resulted in a dose-dependent wavelength shift upon target incubation. These reagents can be used in experiments and devices to create simpler and more efficient biosensors across a range of research, medical laboratory, and point-of-care platforms. © 2023 American Chemical Society.
Keywords: genetics; peptide; chemistry; immunoglobulin fragment; peptides; immunoassay; antibodies; genetic procedures; troponin i; antibody; immunoglobulin fragments; procedures; biosensing techniques
Journal Title: ACS Chemical Biology
Volume: 18
Issue: 8
ISSN: 1554-8929
Publisher: American Chemical Society  
Date Published: 2023-08-18
Start Page: 1863
End Page: 1871
Language: English
DOI: 10.1021/acschembio.3c00303
PUBMED: 37440171
PROVIDER: scopus
DOI/URL:
Notes: Article -- Source: Scopus
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  1. Daniel Alan Heller
    112 Heller
  2. Zvi Aharon Yaari
    11 Yaari
  3. Mijin Kim
    12 Kim