ITC binding assay of wildtype IPO (tetremeric IPO) with carbohydrates.

For the methylated carbohydrates, the thermal changes were detected with 1 mM wildtype IPO which was titrated by 25 mM Me-Man (A), 25 mM Me-Glc (B), 25 mM Me-Gal (C). For the non-methylated carbohydrates, the thermal changes were detected with 3 mM IPO which was titrated by 75 mM Man (D), 75 mM Glc (E) and 75 mM Gal (F). The upper panel of figures was presented by 18 injections and 2 µl/per injection. The interval of injection time is 180 sec. The 18 experimental data were almost fitted for a 1∶1 binding model (one-site of fitting) with Microcal Origin 7.0 software (the bottom panel). In each bottom panel, X-axis indicates the molar ratio of protein-carbohydrate and Y-axis indicates the thermal change in each injection.