Figure 6. Sdk1 and Sdk2s’ homophilic interactions are stronger than their heterophilic interaction.
(A) Heterophilic and homophilic Sdk binding were analyzed by a surface plasmon resonance (SPR) experiment. Sdk1Ig1–6 (top row) and Sdk2Ig1–6 (bottom row) were covalently attached to the SPR chip and three different identical concentrations of each Sdk analyte (columns) were flowed over the Sdk1Ig1–6 and Sdk2Ig1–6 surfaces. The binding association and dissociation are shown by the normalized SPR response. (B) Close up of interacting specificity residues 29 and 168 in the Sdk1 (blue) and Sdk2 (orange) dimer interfaces.