Table 5. Binding Energy of 2 inhibitors bound to 3 kinases.

Kinase	PDB	Kinase with Bosutinib	Kinase with Bos-Isomer
Wee1	3BI6	390	448
Chk1	2HY0	449	574
Abl	3UE4	536	526*
Binding energy of inhibitors (kcal/mol)

The binding energy as assessed by the program Yasara³⁶ using the AMBER 2003 force field without long range electrostatics enabled and BindEnergy command. The BindEnergy command calculates the binding energy of the inhibitor with respect to the rest of the protein according to the current force field.³⁷ The binding energy is obtained by calculating the energy at infinite distance (between the inhibitor and solvent, i.e., the unbound state) and subtracting the bound state. The more positive the binding energy, the more favorable the interaction in the context of the chosen force field. The starting coordinates for the 3 proteins were obtained from the listed PDB codes.