Analysis of septin rod stability and the interaction of Bni5 with the rod via SPR. A. Septin rods are stable when immobilized to SPR sensor chips. (1) Capture of biotinylated rods to the anti-biotin antibody coated SPR chip, (2) capture baseline, (3a,b) injection of anti S tag antibody, (4a,b) dissociation, (5) regeneration of the chip surface. B. Determination of the KD (3.13x10-7 M) of the interaction of Bni5 with immobilized septin rods from the fit of the analyte response plotted against the respective analyte concentration (representative plot from a series of experiments). C. Determination of the kinetics parameters from the same dataset as shown in B. The analyte response sensograms were fitted with a two state reaction model to obtain KD (2,53x10-7 M), kon (5,1x104 M-1s-1) and koff (0,037 s-1) (representative plot from a series of experiments).