A colorimetric assay of DNA methyltransferase activity based on peroxidase mimicking of DNA template Ag/Pt bimetallic nanoclusters

Abstract

DNA methylation catalyzed by DNA methyl transferase (MTase) is a significant epigenetic process for modulating gene expression. Abnormal levels of DNA MTase enzyme have been regarded as a cancer biomarker or a sign of bacterial diseases. We developed a novel colorimetric method to assay M.SssI MTase activity employing peroxidase-like activity of DNA template Ag/Pt NCs without using restriction enzymes. Based on inhibiting the peroxidase reaction that occurred in the TMB-HO system, in the presence of MTase, a highly sensitive and selective colorimetric biosensor was fabricated with a detection limit (LOD) of 0.05 U/mL and a linear range from 0.5 to 10 U/mL. The changes in absorption intensity were monitored to quantify the M.SssI activity. This strategy had a high selectivity over other proteins. Furthermore, it is also demonstrated that this method can be used for the evaluation and screening of inhibitors for DNA MTase.

Probing low abundant DNA methylation by CRISPR-Cas12a-assisted cascade exponential amplification

“…In addition, the MSP assay only provides qualitative results instead of quantitative data due to the visual readout of detection results via agarose gel electrophoresis. In recent years, a variety of PCR-free strategies have been developed for the sensitive quantification of DNA methylation, such as fluorescence assay, 12,13 electrochemical enzymatic assay, 14 colorimetry, [15][16][17] and Raman spectroscopy. 18,19 Shiddiky et al reported a global DNA methylation screening method in a PCR-free way by utilizing electrochemical enzymatic signal engagement.…”

Peroxidase Effect of Ce2(WO4)3 Nanoparticles to Detection of Glucose as a Colorimetric Sensor

“…Compared with natural enzymes, nanozymes have higher stability and multifunctionality leading to their numerous application. [1][2][3][4][5][6] Nanozymes have also been used in biosensors to detect different molecules, cancer cells, and other targets. [7][8][9][10][11][12][13] To date, an extensive range of nanozymes with enzymatic properties for detection of glucose has been reported; for instance, Au NPs, Ag NPs, Pt NPs and their alloys, [14] carbon-based nanomaterials, [15][16][17] metal-organic frameworks (MOFs), [18] Tungsten disulfide (WS 2 ) nanosheets, [15] etc.…”

“…Some of these nanomaterials have been studied extensively and yielded acceptable results. Compared with natural enzymes, nanozymes have higher stability and multifunctionality leading to their numerous application [1–6] . Nanozymes have also been used in biosensors to detect different molecules, cancer cells, and other targets [7–13] .…”

Sensitive detection of methylated DNA and methyltransferase activity based on the lighting up of FAM-labeled DNA quenched fluorescence by gold nanoparticles

“…[7][8][9][10] The conventional methods for the detection of MTase enzyme activity and methylated DNA include bisulte treatment, 11 high performance liquid chromatography (HPLC), 12 electrochemistry, [13][14][15][16][17] enzyme-linked immunosorbent assay (ELISA), 18 surface plasmon resonance (SPR) spectroscopy, 19,20 surface-enhanced Raman scattering (SERS), 21,22 and use of microuidic based biosensors 23,24 and uorescence based biosensors. [25][26][27][28] Although several attempts have been made for the detection of methylated DNA in recent years, there are still some drawbacks that limit their sensitivity and efficacy in clinical applications.…”