Fig. 3: Engineered NgAgo-gDNA binds to target nucleic acids with high affinity.
a SPR dynamic curves of the interaction between target DNA and NgAgo-gDNA complex of different concentrations. b Calibration curves of SPR, data presented as the mean values ± SDs, n = 3 independent experiments. c The affinity constant of target DNA and the NgAgo-gDNA complex validated by the SPR method. d The recognition ability of different gDNA-guided NgAgo systems to target DNA with and without a graphene surface; pink and yellow backgrounds refer to the graphene interface and no graphene interface, respectively, using 50 mM [Fe(CN)6]3–/4–. For the graphene interface group, NgAgo was immobilized on this surface, and 1% BSA blocked the nonactive sites. gDNA was then anchored by NgAgo. For the no graphene interface group, thioglycolic acid was first immobilized on the surface of the gold microelectrode, and the following process was the same as that for the graphene interface group, using two-way ANOVA: *p < 0.05, **p < 0.01, ***p < 0.001, ****p < 0.0001, p value of 0.000511, 0.000322, 0.000479, for sepsis, organ, NTC groups respectively, data presented as the mean values ± SDs, n = 3 independent experiments. e The predicted modeling of NgAgo-gDNA (i) and the indicated domain of NgAgo protein (ii) containing RepA, N-terminus, PAZ, MID, PIWI, the color-coded surface charge distribution of the complex, (iii) to (v) referring to front, right, left view, respectively.
