Table 4. Comparison of the absolute free energies^a of the different conformations of the loops.

Model	Conformations	ΔEint	ΔEeelc	ΔEvdw	ΔEsp	ΔEnsp	ΔPB	ΔTS	ΔG
anti_bsc0	ANTI_L1-ANTI_L2	−9	85	−4	−91	0	−19	−1	−18
anti_bsc0	ANTI_L4-ANTI_L3	−7	−14	2	17	0	−2	4	−6
hybrid_bsc0	HYBRID_L1-HYBRID_L2	13	−90	−12	57	1	−32	4	−36

Results under parm99 force field are given in Table S3.

^aΔE, internal energy, ΔE, Coulombic energy, ΔE, van der Waals energy, ΔE, polar solvation energy, ΔE, nonpolar solvation energy, ΔPB, enthalpy, ΔTS, solute entropy, ΔG, absolute free energy. All are in kcal/mol.