NMR analysis of P5SA-2 confirms binding of P5SA-2 to PPH-5. P5SA-2 specific peaks (blue) disappear upon addition of 10 μM of PPH-5 (red). The PPH-5 spectrum is shown below for comparison (green). Missing peaks indicate decrease in the P5SA-2 tumbling rate caused by binding to PPH-5. Peaks that do not disappear after protein addition indicate that certain moieties of P5SA-2 are not directly immobilized by PPH-5. Peaks ~7.7 ppm originates from buffer impurities. Measurements were performed in phosphate buffer at 20°C as outlined in the ‘Experimental’ section.