Receptor remains bound to PA domain 4 at pH 5.1.
A) A subset of the 1D slices of the [15N,1H] TROSY-HSQC spectra highlighting several cross-peaks without saturation at pH 5.1 (left panels) or with saturation at pH 5.1 (right panels). Cross-peaks representing PA domain 2 and 4 contact residues are indicated with red and blue labels, respectively. B) A plot of the intensity ratio (Is/Io) from the transferred cross saturation of (PA63)7 to interacting residues on the ANTXR2 VWA domain. Significant cross saturation (Is/Io≤0.75) is indicated with a single asterisk, and highly significant (Is/Io≤0.5) is indicated with a double asterisk. For all graphs the errors were calculated by propagating the base-plane noise, which was derived from the signal-to-noise ratios of both interleaved experiments. The data was taken from two separate experiments performed at pH 5.1 and pH 5.15 and the average was derived from these experiments.
