¹³C-HMQC NMR demonstrating the Cx26 CT 14mer does not complex with taurine. (A) The spectrum of the Cx26CT alone (black) is overlaid with its spectrum in excess taurine (red) at a 1:7.5 molar ratio. The two overlays (left vs. right) differ in the proton region selected for observation. (B) Close-up of a spectrum of each of the two methyl (-CH₂-) groups of taurine (black) overlaid with the same spectrum of taurine in excess Cx26CT (red) at a 1:3 molar ratio. (Left) The methyl group closest to the sulfonate moiety (-SO₃H). (Right) The methyl group closest to the amine (-NH₂). In both cases, the resonance centers do not change, which further indicates lack of interaction between taurine and the Cx26CT peptide.