Table 1. Predicted Values for ³J Couplings at χ₁ Rotamer Angles of 180°, 60°, and −60°^a.

	3JCγN (Hz)			3JCγCO (Hz)
residue type	Jt	Jg	Jh	Jt	Jg	Jh
His	2.73	0.50	0.50	1.09	1.09	4.97
Phe, Trp, Tyr	2.62	0.38	0.38	0.55	0.55	4.43
Ile	0.95	0.31	2.01	0.79	3.83	0.45
Thr	0.27	0.73	1.65	1.18	3.35	0.18
Val Cγ1	2.00	0.47	0.68	0.45	0.79	3.83
Val Cγ2	0.31	2.01	0.95	3.83	0.45	0.79

^aExpected ³J values for fully populated staggered rotamers. All values are given with respect to the χ₁ angle. Values for the aromatic residues are derived from fits of Karplus curves to the DHFR ³J data vs the χ₁ angle as reported previously.¹² Values for the γ-methyl residues are from the parametrizations of Chou et al.⁴⁸ Plots of each Karplus curve are shown in Figure S1 of the Supporting Information.