To obtain more quantitative data in solution on the oligomerization state of our samples we performed sedimentation velocity experiments (SV) at two loading concentrations (~0.3 and ~0.9 OD280). Diffusion corrected van Holde–Weischet sedimentation coefficient distributions of LPHN3-OLF and the OLF-LRR complex indicated single homogeneous species that did not change sedimentation distribution as a function of loading concentration (4.1 μM and 13.5 μM for LPHN3-OLF, and 2.4 μM and 7.5 μM for the OLF-LRR complex) (Figure 1D). These data indicate that LPHN3-OLF is a monomer with an estimated molecular weight of 37,195Da and 37,340Da for the low and high concentrations respectively, in line with the 36.6 kDa value calculated from the sequence of our expressed protein. The OLF-LRR complex behaves a 1:1 assembly with an estimated molecular weight of ~95KDa, a value compatible to the mass of the glycosylated complex (~81.9Da). To characterize the apparent dimerization of FRLT3-LRR, samples were measured in the AUC at 2 loading concentrations 0.38 and 0.92 OD 280, corresponding to 7.6 and 18.3 μM, respectively. The van Holde – Weischet analysis shows a strong mass action
