The incorporation of hemin into the G-quadruplex structure of DNAzyme yields an active HRP-like activity that catalyzes luminol to generate a chemiluminescence (CL) signal.
The structure of the engineered single-stranded DNA (ssDNA) includes the horseradish peroxidase (HRP -like DNAzyme, optimum-lengtHRP -like(10-mer-length DNAzymend target-specific aptamer sequences.
The G-quadruplex hemin complexes possess horseradish peroxidase (HRP)-like activity, and therefore, the HRP-mimickinG-quadruplex hemin) complexes possessation in thorseradish of luminol and H2O2.
The tetraplex structural motif found in HRP-like DNAzymes has been also used to develop fluorescence probes for potassium ion or pH monitoring [ 29, 40, 172– 172].
In this study, the plesiomorphic genotype for this genus was predicted to contain an Hrp-like T3SS, a single flagellal locus (Flg-1), two T6SS loci (T6SS-1 and T6SS-2), two expolysaccharides (lscC and stewartan), and the sorbitol metabolism (srl) operon.
In the absence of the target metal ion, these three domains acted cooperatively in the DNA-cleaving active state as a result of strong intramolecular interactions, and the resulting structure revealed higher stability than the G-quadruplex structure responsible for activity of HRP-like DNAzyme2.
When the target Cu II) ion was present, cleavage of a substrate by DNAzyme1 disturbed the intramolecular DNA conformation, and this event resulted in an allosteric transformation from the active state of DNAzyme1 to the active state of HRP-like DNAzyme2 with a tetraplex structure, which in turn gave a colorimetric signal [ 171].
Advantages to this include the ability to use enzyme-coupled assays (like HRP) or substrates of poor solubility or viscosity.
Thus it seems likely that acquisition of the hrp gene cluster, like the gum cluster, was a relatively late adaptation in the lineage that led to the Xanthomonas strains in the present study.
AA = adjuvant arthritis; AUC = area under the curve; BSA = bovine serum albumin; DMEM = Dulbecco's modified Eagle's medium; ELISA = enzyme-linked immunosorbent assay; FCS = fetal calf serum; FLS = fibroblast-like synoviocytes; HRP = horseradish peroxidase; i.a.a
Both the overall fold and the heme cavity architecture of heme peroxidases like HRP or MPO are completely different compared to those of Cld.
