Microcal peaq itc analyze software

The interaction between 2,4-DAPG and PltZ was measured using ITC at 25°C with a MicroCal PEAQ-ITC instrument (Malvern, United States). One millimolar 2,4-DAPG solution used for titration was prepared with the ITC buffer (20 mM Tris, pH 8.0, 100 mM NaCl). Protein samples were prepared by dialysis in the ITC buffer. The concentrations of PltZ and 2,4-DAPG were both 25 μM. The protein and ligand solutions were centrifuged at 12,000 × g for 30 min before titration. The titration was performed with a total of 19 injections of 40 μl 2,4-DAPG into the PltZ solution (200 μl). 2,4-DAPG was also titrated into the ITC buffer alone, and the resulting heat of dilution was subtracted from the experimental curve. Data analyses were performed with the MicroCal PEAQ-ITC Analyze software, and an independent binding model was used to calculate the thermodynamic parameters of interaction between PltZ and 2,4-DAPG.