Title
Engineering Oligonucleotide-Based Peroxidase Mimetics for Colorimetric Assay of S1 Nuclease
Author
Chuan He, Jinli Zhang, Wei Li, Yan Fu
Year
2018
Journal
Analytical Methods
Abstract
Herein we propose a rational design to construct peroxidase mimetics in response to S1 nuclease by employing guanine-rich oligonucleotides and Cu2+ ions. The enzymatic activities of DNA-Cu(II) are highly dependent upon the binding stoichiometry between Cu2+ and DNA. In the H2O2-mediated oxidation of 3,3',5,5'-tetramethylbenzidine, the catalytic activity of Cu2+ can be accelerated by approximately 88-times in the presence of AG3(T2AG3)3, whereas it shows slight enhancement in the presence of mononucleotide (GMP). The coordination of Cu2+ within DNA structures greatly strengthens its ability to generate reactive oxygen species. The most intriguing finding in this study is that DNA-Cu(II) complexes lose their enzymatic activities after the cleavage of DNA scaffolds by S1 nuclease. A colorimetric method was established for selectively evaluating S1 nuclease activity with the limit of detection of 4.7×10-3 U/mL, only by using label-free oligonucleotides and copper ions without complicated synthesis and apparatus. This facile method can also be applicable for quantitative analysis in biological fluids.
Instrument
J-810
Keywords
Circular dichroism, DNA structure, Chemical stability, Biochemistry