TABLE 2.

Factoring hyperfine shifts for heme and His(F8) of Aplysia metMbCN

	Aplysia metMbCN					Sperm whale MetMbCN
Proton	δDSS(obs)*	δDSS(dia)†	δhf‡	δdip(calc)§	δcon¶	δcon‖
Heme
1-CH3	11.80	3.6 ± 0.1	8.2 ± 0.1	−2.8 ± 0.3	11.0 ± 0.4	18.0 ± 0.2
3-CH3	17.79	3.6 ± 0.1	14.2 ± 0.1	−5.0 ± 0.4	19.2 ± 0.5	6.0 ± 0.2
5-CH3	15.62	2.8 ± 0.2	12.8 ± 0.1	−3.3 ± 0.3	15.3 ± 0.4	27.5 ± 0.2
8-CH3	9.95	3.6 ± 0.1	6.3 ± 0.1	−4.0 ± 0.3	10.4 ± 0.4	14.7 ± 0.2
6-Hαs**	16.5	3.5 ± 0.5	13.0 ± 0.5	−3.6 ± 0.8	16.6 ± 1.3
7-Hαs**	4.3	3.5 ± 0.5	0.8 ± 0.5	−4.5 ± 1.0	5.3 ± 1.5
α-meso-H	0.96	10.0 ± 0.5	−9.0 ± 0.5	−11.7 ± 1.2	2.7 ± 1.7	6.6 ± 0.5
β-meso-H	5.93	10.0 ± 0.5	−4.1 ± 0.5	−8.3 ± 1.0	4.2 ± 1.5	2.8 ± 0.4
γ-meso-H	−0.44	10.0 ± 0.5	−10.4 ± 0.5	−12.9 ± 1.4	2.5 ± 1.9	6.3 ± 0.4
δ-meso-H	4.99	10.0 ± 0.05	5.0 ± 0.5	−6.9 ± 1.1	1.9 ± 16	6.1 ± 0.5
His(F8)
Cβ1H	10.55	1.2 ± 0.2	9.3 ± 0.2	6.5 ± 0.8	2.8 ± 1.0	3.4 ± 0.2
Cβ2H	10.73	1.2 ± 0.2	9.5 ± 0.2	6.8 ± 0.8	2.7 ± 1.0	0.8 ± 0.2
CɛH	−2.35	1.6 ± 0.2	−4.0 ± 0.2	18.0 ± 2.0	−22.0 ± 2.0	19.0 ± 1
CδH	18.35	1.3 ± 0.2	−17.0 ± 0.2	25.0 ± 3.0	−8.0 ± 3.0	−1.1 ± 0.8
NδH	14.30	9.0 ± 1.0	5.3 ± 1.0	9.9 ± 0.9	−4.6 ± 1.9	−3.5 ± 0.3

^*Chemical shift in ppm, referenced to DSS, in ²H₂O at pH 8.6 and 25°C.

^†Chemical shift of a diamagnetic structural analog.

^‡Hyperfine shift, in ppm at 25°C, defined as δ_DSS(obs)−δ_DSS(dia).

^§Dipolar shift, in ppm at 25°C, as calculated from the optimized magnetic axes for data set II in Table 1.

^¶Contact shift, in ppm at 25°C, obtained from Eqs. 1 and 2.

^‖Previously reported (29) contact shift, in ppm at 25°C, for sperm whale metMbCN in ²H₂O at pH 8.6.

^**Mean of the geminal protons.