Characterization of two TA8-derived variants, 2H7 and 3C12.

(A) Evaluating the specificity of the 2H7 monobody by probing arrays of 150 human SH3 domains, which have been spotted in duplicate. Values plotted on the y-axis of the histogram represent relative units, with error bars corresponding to the standard deviations of signal intensities of duplicate spots. (B) The dissociation constants (K_Ds) of two TA8 variants, 2H7 and 3C12, were determined by ITC. For the two representative experiments shown here, the observed N, ΔH, and ΔS values for 2H7 and 3C12 are 0.998, -1.43 × 10⁴ cal/mol, -13.3 cal/mol/deg and 0.966, -1.6 × 10⁴ cal/mol, -20.2 cal/mol/deg, respectively. The ITC experiments were performed three times for each variant; the average K_D values for 2H7 and 3C12 were measured to be 40 ± 15 and 42 ± 10 nM, respectively.