NMR spectra were acquired at 298 K on a Bruker 500 MHz spectrometer using a TXO CRPHe TR-13 C/ 15 N/ 1 H 5 mm-Z CryoProbe. The samples were dissolved in D2O, and referenced to the residual solvent peak at 4.87 ppm in the 1 H NMR spectrum, or to MeOH at 49.86 ppm which was added as an external reference for the 13 C NMR spectrum. H NMR spectra were gathered over 330 scans, with a 3.28 s acquisition time, and a 15.3 s relaxation delay. C NMR spectra were gathered over 9600 scans, with a 0.92 s acquisition time, and an 8 s relaxation delay.