Figure 2. The principle of Transferred Cross Saturation (TCS) applied to the (PA₆₃)₇-ANTXR2 complex.

A) Schematic of TCS between ANTXR2 VWA domain and the PA₆₃ pore. ²H¹⁵N-labeled ANTXR2 VWA-domain was mixed at a ratio of (10∶1) with PA₆₃ heptamer. Radiofrequency pulses were applied to the sample, in order to saturate the aliphatic protons of the PA₆₃ heptamer. Saturation is then transferred to the contact residues of the labeled ANTXR2 VWA-domain, reducing the intensity of the corresponding cross peaks in the spectrum. B) Saturated and unsaturated spectra of the (PA₆₃)₇-ANTXR2 complex at pH 8.0. The [¹H,¹⁵N] TROSY-HSQC spectra of the ²H-¹⁵N labeled ANTXR2-VWA domain complexed with the PA₆₃ heptameric prepore are shown overlayed under saturating or non-saturating (black) conditions.