Activatable G-quadruplex based catalases for signal transduction in biosensing

Abstract

Discovery of oxidative catalysis with G-quadruplex•hemin constructs prompted a range of exciting developments in the field of biosensor design. Thus, G-quadruplex based DNAzymes with peroxidase activity found a niche as signal transduction modules in a wide range of analytical applications. The ability of nucleic acid scaffolds to recognise a variety of practically meaningful markers and to translate the recognition events into conformational changes powers numerous sensor design possibilities. In this work, we establish a catalase activity of G-quadruplex•hemin scaffolds. Catalase activated hydrogen peroxide decomposition generates molecular oxygen that forms bubbles. Observation of bubbles is a truly equipment free signal readout platform that is highly desirable in limited resources or do-it-yourself environments. We take a preliminary insight into a G-quadruplex structure—folding topology—catalase activity correlation and establish efficient operating conditions. Further, we demonstrate the platform's potential as a signal transduction modality for reporting on biomolecular recognition using an oligonucleotide as a proof—of—concept target. Ultimately, activatable catalases based on G-quadruplex•hemin scaffolds promise to become valuable contributors towards accessible molecular diagnostics applications.

Aptamer and DNAzyme-Functionalized Cu-MOF Hybrid Nanozymes for the Monitoring and Management of Bacteria-Infected Wounds

“…Figures B,C and S7 show that in the GATC + H 2 O 2 system, the reduction of H 2 O 2 by GATC exhibited higher CAT-like activity, resulting in lower absorbance of the remaining H 2 O 2 than in the other two systems. The results shown in Figure S8 suggested that a portion of the CAT-like activity of GATC originated from Au-TA and Apt-DNAzyme. , …”

DNA Robots for CRISPR/Cas12a Activity Management and Universal Platforms for Biosensing

“…In the presence of hAAG, it recognized dsDNA-I and generated an AP site, which could inhibit the activation of Cas12a and prevent cleavage of G4 (Figure a). Intact G4 could combine with hemin to exert peroxide-like activity and oxidize TMB to produce blue products oxTMB under the catalysis of H 2 O 2 . When hAAG was absent, dsDNA-I remained unchanged and could activate Cas12a to cleave G4.…”

“…Intact G4 could combine with hemin to exert peroxide-like activity and oxidize TMB to produce blue products oxTMB under the catalysis of H 2 O 2 . 34 When hAAG was absent, dsDNA-I remained unchanged and could activate Cas12a to cleave G4. Therefore, there was no G4 in the system that could bind with hemin to oxidize TMB, and the color remained unchanged.…”

Flipons: The discovery of Z-DNA and soft-wired genomes

“…Intriguingly, biofilms also undergo G4Q formation [114]. In the presence of hemin, a normal component of serum, the G4Q acts as an enzyme and can generate hydrogen peroxide in addition to that produced by the protein enzymes released from neutrophil granules [115]. Hydrogen peroxide is a highly bactericidal chemical species.…”