SAM / Kd
Binding
Dissociation Constant (Kd)
mM (milliMolar)
Isothermal Titration Calorimetry (ITC)
20 mM sodium phosphate, 50 mM NaCl, and 10 mM MgCl2
25ºC
7.5
64.8 10-6M
None
None
ITC studies were performed at 25 °C with a MicroCal VP-ITC (Malvern). A 1.5-mM SAM solution was titrated into a solution of MeT1 (64.8 μM). All experiments involved an initial injection of 3 μL of SAM solution, followed by a series of 12-μL injections (8-min interval between consecutive injections) of ligand solution into a sample cell continuously stirred at 307 rpm. The heat of ligand dilution into buffer was subtracted from the reaction heat data. All data were analyzed and fitted to the one binding site model using the Origin 7.0 software package (OriginLab).