version date: 1 December 2006 10 2000 4000 Hint Score Fig. 2 Plots of experimental AG vS. HINT score units for bovine trypsin(cyan triangle)and tryptophane synthase(green triangle) The regression analyses of bovine trypsin and tryptophan synthase data series are shown in Fig. 2 and, respectively, represented by the following equations AG°=-0.0019HSpL-3.1210 △G°=-00028HSpL-0.5880 with R=0.83,(standard error) SE=0.90 kcal/mol for trypsin-ligand complexes andR=0.87 and SE=1.16 kcal/mol for tryptophan synthase-ligand complexes Thus, it is possible to predict the binding free energy of new hypothetical trypsin or tryptophan synthase ligands, for which the experimental inhibition constant value has not been yet determined just calculating the hinT score value for the new potential complex, as shown in Fig 3 <www.iupac.org/publications/cd/medicinalchemistry/>9 Fig. 2 Plots of experimental ∆G° vs. HINT score units for bovine trypsin (cyan triangle) and tryptophane synthase (green triangle). The regression analyses of bovine trypsin and tryptophan synthase data series are shown in Fig. 2 and, respectively, represented by the following equations: ∆G° = –0.0019 HSP–L –3.1210 ∆G° = –0.0028 HSP–L –0.5880 with R = 0.83, (standard error) SE = 0.90 kcal/mol for trypsin-ligand complexes and R = 0.87 and SE = 1.16 kcal/mol for tryptophan synthase-ligand complexes. Thus, it is possible to predict the binding free energy of new hypothetical trypsin or tryptophan synthase ligands, for which the experimental inhibition constant value has not been yet determined, just calculating the HINT score value for the new potential complex, as shown in Fig. 3. Hint Score 0 1000 2000 3000 4000 ∆G° (kcal/mol) -2 -4 -6 -8 -10 <www.iupac.org/publications/cd/medicinal_chemistry/> version date: 1 December 2006