8DZV

Chicken anti-cardiac Troponin I antibody in complex with peptide

Summary for 8DZV

• Entry DOI: 10.2210/pdb8dzv/pdb
• Descriptor: scfv 2B12, cTnI peptide, POTASSIUM ION, ... (5 entities in total)
• Functional Keywords: scfv, chicken, ctni, complex, protein binding
• Biological source: Gallus gallus (Chicken); More
• Total number of polymer chains: 2
• Total formula weight: 30286.84

Authors

Conroy, P.J.,Law, H.P. (deposition date: 2022-08-08, release date: 2023-07-26, Last modification date: 2024-10-23)

Primary citation

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.
Design of Polarity-Dependent Immunosensors Based on the Structural Analysis of Engineered Antibodies.
Acs Chem.Biol., 18:1863-1871, 2023

PubMed 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.

PubMed: 37440171
DOI: 10.1021/acschembio.3c00303

Experimental method

X-RAY DIFFRACTION (1.2 Å)