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Application of CdTe/CdS/ZnS quantum dot in immunoassay for aflatoxin B1 and molecular modeling of antibody recognition.
- Source :
-
Analytica chimica acta [Anal Chim Acta] 2019 Jan 24; Vol. 1047, pp. 139-149. Date of Electronic Publication: 2018 Sep 26. - Publication Year :
- 2019
-
Abstract
- In order to develop a sensitive immunoassay for Aflatoxin B1 (AFB1) monitoring, a hybridoma secreting anti-AFB1 monoclonal antibody with high binding affinity was screened. A new type of CdTe/CdS/ZnS quantum dot was synthesized and conjugated with an artificial antigen for use as a fluorescent probe in a simple one-step fluorescence immunoassay (FLISA). The developed FLISA allowed a sensitive determination of AFB1 in cereal samples in a wide linear range, from 0.08 to 1.97 ng mL <superscript>-1</superscript> , with a detection limit of 0.01 ng mL <superscript>-1</superscript> in cereal samples. The corresponding immunoglobulin genes of the Fab fragment were cloned and sequenced, and expression of Fab was successfully verified in HEK293 cells, with a K <subscript>D</subscript> value of 1.09 × 10 <superscript>-7</superscript> mol L <superscript>-1</superscript> for AFB1. To investigate the interactions between the antibody and AFB1, molecular docking, molecular dynamic simulation, and quantum-chemical computation were performed on AFB1 and a homology model of the Fab fragment. Our results showed that residues Ser32, Trp93, and Trp98 played the most important roles in the binding through hydrogen bonds formation, Pi-Pi stacked/Pi-alkyl interactions, and van der Waals interactions. In addition, the electrostatic potential study of AFB1 demonstrated that electrostatic interactions also played an important role in the recognition process. Results from theoretical studies provide guidance for hapten design and antibody improvement through genetic engineering.<br /> (Copyright © 2018 Elsevier B.V. All rights reserved.)
- Subjects :
- Aflatoxin B1 chemistry
Aflatoxin B1 immunology
Antibodies, Monoclonal chemistry
Cadmium Compounds chemistry
Edible Grain chemistry
Fluorescence
HEK293 Cells
Humans
Immunoglobulin Fab Fragments chemistry
Immunoglobulin Fab Fragments immunology
Limit of Detection
Molecular Docking Simulation
Molecular Dynamics Simulation
Sulfides chemistry
Tellurium chemistry
Zinc Compounds chemistry
Aflatoxin B1 analysis
Antibodies, Monoclonal immunology
Fluorescent Dyes chemistry
Food Contamination analysis
Immunoassay methods
Quantum Dots chemistry
Subjects
Details
- Language :
- English
- ISSN :
- 1873-4324
- Volume :
- 1047
- Database :
- MEDLINE
- Journal :
- Analytica chimica acta
- Publication Type :
- Academic Journal
- Accession number :
- 30567644
- Full Text :
- https://doi.org/10.1016/j.aca.2018.09.058