Fig. 3. IgLON homodimers have different binding affinities. Fluorescent beads coupled to protein G coated with recombinant LAMP-Fc, OBCAM-Fc or CEPU-1-Fc were allowed to aggregate for 15 minutes and analysed by flow cytometry. (A) CEPU-1-Fc-coated beads showed the best aggregation, with only 22% of beads remaining single, compared with 30% for OBCAM-Fc and 45% for LAMP-Fc. An unrelated lymphocyte protein Ox40-HuIg Fc gave 68%, and protein-G-coupled beads gave 80% (n=4). CEPU-1 and OBCAM were significantly different from LAMP (P<0.004 and P<0.04, respectively). (B) CEPU-1-Fc-coated beads formed larger aggregates than LAMP-Fc-coated beads. The number of single CEPU-1-Fc beads was small compared with single LAMP beads, and the number of CEPU-1 aggregates with three or more beads was much larger.