title: Enzyme-regulated activation of DNAzyme: a novel strategy for a label-free colorimetric DNA ligase assay and ligase-based biosensing.
abstract: The DNA nick repair catalyzed by DNA ligase is significant for fundamental life processes, such as the replication, repair, and recombination of nucleic acids. Here, we have employed ligase to regulate DNAzyme activity and developed a homogeneous, colorimetric, label-free and DNAzyme-based strategy to detect DNA ligase activity. This novel strategy relies on the ligation-trigged activation or production of horseradish peroxidase mimicking DNAzyme that catalyzes the generation of a color change signal; this results in a colorimetric assay of DNA ligase activity. Using T4 DNA ligase as a model, we have proposed two approaches to demonstrate the validity of the DNAzyme strategy. The first approach utilizes an allosteric hairpin-DNAzyme probe specifically responsive to DNA ligation; this approach has a wide detection range from 0.2 to 40 U mL(-1) and a detection limit of 0.2 U mL(-1). Furthermore, the approach was adapted to probe nucleic acid phosphorylation and single nucleotide mismatch. The second approach employs a "split DNA machine" to produce numerous DNAzymes after being reassembled by DNA ligase; this greatly enhances the detection sensitivity by a signal amplification cascade to achieve a detection limit of 0.01 U mL(-1).
authors.affiliation: State Key Laboratory of Chemo/Biosensing and Chemometrics, College of Chemistry and Chemical Engineering, Hunan University, Changsha 410082, PR China.
authors.forename: Kaiyu
authors.initials: K
authors.lastname: He
authors.forename: Wang
authors.initials: W
authors.lastname: Li
authors.forename: Zhou
authors.initials: Z
authors.lastname: Nie
authors.forename: Yan
authors.initials: Y
authors.lastname: Huang
authors.forename: Zhuoliang
authors.initials: Z
authors.lastname: Liu
authors.forename: Lihua
authors.initials: L
authors.lastname: Nie
authors.forename: Shouzhuo
authors.initials: S
authors.lastname: Yao
mesh_terms: D003124:Colorimetry / Q000379:methods*; D004247:DNA / Q000737:chemistry*; D000072481:DNA Ligase ATP; D011088:DNA Ligases / Q000032:analysis / Q000378:metabolism*; D021881:DNA, Catalytic / Q000378:metabolism*; D006735:Horseradish Peroxidase / Q000378:metabolism; D008958:Models, Molecular; D009690:Nucleic Acid Conformation; D009693:Nucleic Acid Hybridization
chemical_list: D021881:DNA, Catalytic; D004247:DNA; D006735:Horseradish Peroxidase; D011088:DNA Ligases; D000072481:DNA Ligase ATP