An electrochemical one-step system for assaying methyltransferase activity based on transport of a quantum dot signaling tracer

作者：Baek Songyi; Won Byoung Yeon; Park Ki Soo; Park Hyun Gyu^*

来源：Biosensors and Bioelectronics, 2013, 49: 542-546.

DOI：10.1016/j.bios.2013.04.036

• DNA methylation
• Methyltransferase
• Epigenetic analysis
• Electrochemical biosensor
• Quantum dot

A one-step, electrochemical method for assaying methyltransferase (MTase) activity, based on the convective transport of a quantum dot (QD) signaling tracer, has been developed. The assay chip used in this system was prepared by modifying a gold matrix with CdSe/ZnS QD-tagged dsDNA, which contains a specific methylation site (5'-GATC-3') recognized by MTase. Treatment of the chip with DNA adenine methylation (Dam) MTase, generates a methylated sequence (5'-GAmTC-3') within the dsDNA. The methylated dsDNA is then subjected to a cleavage reaction, induced by DpnI, which leads to release from the gold matrix of a DNA fragment tethered to a QD. Detection of the released QD, using square wave anodic stripping voltammetry (SWASV) on a glassy carbon (GC) electrode, enables the reliable quantitation of the methylated DNA. Because it is accomplished in a simple and convenient one step and does not require any complicated secondary or tedious washing steps, the new assay method holds great promise for epigenetic analysis in facility-limited environments or point-of-care testing (POCT) applications.

• 出版日期2013-11-15