Novel method to detect DNA methylation using gold nanoparticles coupled with enzyme-linkage reactions.
DNA methylation, catalyzed by methylases, plays a critical role in many biological processes, and methylases have been regarded as promising targets for antimicrobial drugs. In this paper, we propose a simple and sensitive colorimetric assay method to detect the activity of methylases so as to monitor DNA methylation using DNA-modified gold nanoparticles (AuNPs) coupled with enzyme-linkage reactions. The duplex DNA molecules modified on the surface of AuNPs are first methylated by DNA adenine methylation (Dam) methyltransferase (MTase) and then cut by methylation-sensitive restriction endonuclease Dpn I. Removal of duplex from the AuNP surfaces by the methylation/cleavage process will destabilize the nanoparticles, resulting in aggregation of AuNPs and a red-to-blue color change. Consequently, the enzyme activity of Dam MTase can be assayed and DNA methylation can be detected. Furthermore, this study may provide a sensitive platform to screen inhibitors for Dam MTase.
Liu
Tao
T
Department of Biochemistry and National Key Laboratory of Pharmaceutical Biotechnology, Nanjing University, Nanjing 210093, P. R. China.
Zhao
Jing
J
Zhang
Dongmei
D
Li
Genxi
G
D003124:Colorimetry / Q000379:methods*; D004247:DNA / Q000737:chemistry*; D019175:DNA Methylation; D015254:DNA Modification Methylases; D003850:Deoxyribonuclease I; D006046:Gold / Q000737:chemistry*; D053768:Metal Nanoparticles / Q000737:chemistry*; D012680:Sensitivity and Specificity
D006046:Gold; D004247:DNA; D015254:DNA Modification Methylases; D003850:Deoxyribonuclease I