Figure 3.

HP ¹²⁹Xe NMR spectra of racemic C7B binding to wild-type carbonic anhydrase II. The C7B biosensor (176 μM) was dissolved in Tris-SO₄ buffer (50 mM, pH 8.0) and 10% glycerol. Solution of 1.3 mM CAII in matched Tris-SO₄ buffer was titrated to give 1:1 stoichiometry with racemic C7B. The chemical shifts for the two “bound” peaks (72.5, 67.9 ppm) are somewhat shifted from the spectrum in reference [33] due to differences in buffer conditions.