The details of the original and modified parameters for dihedral angles on the backbone.

Dihedral angle	Original parameters			Modified parameters
	K 1 (kcal mol−1)	K 2 (kcal mol−1)	K 3 (kcal mol−1)		K 1 (kcal mol−1)	K 2 (kcal mol−1)	K 3 (kcal mol−1)
(1) C4–C4–C3 –C3	0.243	0	0.104		−0.010	−0.200	−0.304
(2) C3 –C4–C4–C3	0	0	−0.153		0.1500	0	−0.353
(3) C3 –C4–C4–C43	0	0	−0.153		0.1500	0	−0.353
(4) C4–C4–C43–C3	0.088	0	−0.020		0.1000	0	−0.198
(5) C4–C4–C43–C4	0	0.051	−0.143		0	−0.100	−0.430
(6) C43–C4–C3 –C3	0.243	0	0.104		0.2000	0	−0.2
(7) C3 –C4–C43–C4	0.088	0	−0.020		0.1	0	−0.198
(8) C43–C4–C43–C4	0	0.051	−0.143		0	0.514	−0.01