Wyatt optilab refractive index detector

To generate variable populations of states A and B, S-2P (100 μL, 0.18 mg/mL) was incubated at either 4 °C or 37 °C for four days. Post-incubation, and prior to SEC-MALS injection, an aliquot from each sample was taken and a one-minute pulse-labeling experiment was performed (see above). The resulting bimodal peptide distributions were used to calculate a fraction state A and B. Samples were filtered (0.22 um um hydrophilic polyvinylidene fluoride Ultrafree-MC GV centrifugal filter) prior to SEC-MALS injection. 90 μL of sample (0.18 mg/mL) was then injected onto a Superose 6 increase 10/300 (GE Healthcare) preequilibrated in filtered (0.1 um polyethersulfone Nalgene Rapid-Flow vacuum filter) PBS flowing at 0.5 ml/min at 4 °C. The ÄKTA Pure 25 M1 (Cytiva) chromatography system was coupled to an 18-angle light scattering Wyatt Dawn detector and Wyatt Optilab refractive index detector (Wyatt Technology). Data analysis was carried out using the program ASTRA 7.1.4.8.