Fig. 3
From: DNA aptamer AptERA 2 targets ERA from Staphylococcus aureus and limits GTP hydrolysis
Analysis of AptERA 2 binding specificity and affinity. (a) AptERA 2 binding specificity on ERA structure. Binding of ERA was compared to BSA, 1F8 (Chagas antigenic protein) and to ERA under denaturing conditions (2% SDS). (b) Dissociation constant (Kd) determination for AptERA 2 using the ELONA assay. ERA was used at a constant concentration of 1 µM, and the aptamer was titrated from 62.5 nM to 2 µM. The continuous line shows fitting with a hyperbolic non-linear regression function (Kd = 243 ± 16 nM). (c) Concentration dependence for ERA protein using ELONA assay. The continuous line shows a dose–response sigmoidal fitting (EC50 = 185 ± 3 nM). ERA was titrated from 78 nM to 1 µM. (d) Kd determination using Label-free MST. The aptamer was titrated from 1.6 nM to 3.4 µM. Continuous line shows a non-linear fitting using a sigmoidal function (EC50 = 117 ± 28 nM). Error bars represent the standard error of the mean (s.e.m.) from duplicates. Error bars in (b, c) represent standard deviations (s.d.) from triplicates.
