1. Construction of a chemiluminescent biosensor based on enzymatic extension and click chemistry for sensitive measurement of MGMT activity in human breast tissues.
- Author
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Pan TT, Jiang S, Yuan H, Wang ZY, He MT, and Zhang CY
- Subjects
- Humans, Female, Breast, Limit of Detection, Biosensing Techniques methods, Click Chemistry, DNA Modification Methylases metabolism, DNA Modification Methylases analysis, DNA Repair Enzymes metabolism, DNA Repair Enzymes analysis, Luminescent Measurements methods, Tumor Suppressor Proteins metabolism, Tumor Suppressor Proteins analysis, Breast Neoplasms enzymology
- Abstract
O
6 -methylguanine methyltransferase (MGMT) is responsible for dealkylation of naturally occurring O6 -methylguanines, and it is closely related with DNA replication, transcription, and cancers. Herein, we develop a chemiluminescent biosensor based on enzymatic extension and click chemistry for sensitive measurement of MGMT activity. When MGMT is present, the MGMT-catalyzed demethylation reaction initiates the cleavage of biotinylated dumbbell probes by PvuII restrictive enzyme, releasing two DNA fragments with 3'-OH end. The resultant DNA fragments can trigger terminal transferase (TdT)- and click chemistry-assisted isothermal amplification to obtain abundant G-rich sequences. The G-rich sequences can be captured by magnetic beads to produce a high chemiluminescence signal. This biosensor can greatly amplify the chemiluminescence signal, facilitating label-free and template-free measurement of MGMT. Especially, the introduction of dumbbell probe and PvuII enzyme can efficiently eliminate the false positive and improve the assay specificity. This biosensor possesses high sensitivity with a detection limit of 1.4 × 10-9 ng/μL, and it may accurately quantify the intracellular MGMT. Importantly, this biosensor can be used to screen the MGMT inhibitors and distinguish the MGMT level in breast tumor tissues and normal tissues, with great potential in drug discovery and cancer diagnosis., Competing Interests: Declaration of competing interest The authors declare that they have no known competing financial interests or personal relationships that could have appeared to influence the work reported in this paper., (Copyright © 2024 Elsevier B.V. All rights reserved.)- Published
- 2025
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