8DZV image
Entry Detail
PDB ID:
8DZV
Keywords:
Title:
Chicken anti-cardiac Troponin I antibody in complex with peptide
Biological Source:
Source Organism:
Host Organism:
PDB Version:
Deposition Date:
2022-08-08
Release Date:
2023-07-26
Method Details:
Experimental Method:
Resolution:
1.20 Å
R-Value Free:
0.17
R-Value Work:
0.16
R-Value Observed:
0.16
Space Group:
P 2 21 21
Macromolecular Entities
Polymer Type:polypeptide(L)
Description:scfv 2B12
Chain IDs:A
Chain Length:277
Number of Molecules:1
Biological Source:Gallus gallus
Polymer Type:polypeptide(L)
Description:cTnI peptide
Chain IDs:B (auth: C)
Chain Length:13
Number of Molecules:1
Biological Source:Homo sapiens
Primary Citation
Design of Polarity-Dependent Immunosensors Based on the Structural Analysis of Engineered Antibodies.
Acs Chem.Biol. 18 1863 1871 (2023)
PMID: 37440171 DOI: 10.1021/acschembio.3c00303

Abstact

"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.

Legend

Protein

Chemical

Disease

Primary Citation of related structures