Figure 6.

Binding study by isothermal titration microcalorimetry. Titration of chitohexaose into (A) WT VhChiP, (B) truncated VhChiP, (C) truncated VhChiP mixed with the N-plug peptide, and (D) the synthesized N-plug peptide. Top panels are thermograms and bottom panels are the corresponding heat integrations with theoretical fits using a nonlinear one-site binding function, available in MicroCal PEAQ-ITC analysis software. ITC experiments were performed at 25 °C. The data were corrected for heats of dilution obtained by titration of chitohexaose into buffer (control data offset by +10 μcal.sec⁻¹, top traces). Data presented are mean ± SD from the same set of experiments, which were carried out in triplicate. ITC, isothermal titration microcalorimetry.