Table 2.

Chemical shifts (ppm) for the oxidized Ht series of variants^a,^b

	WT	K22M	M13V	M13V/K22M	(M13V/K22M -WT)c
1H methyl	21.65	21.53	20.91	20.59	−1.06
13C methyl	−36.7	−36.7	−36.4	−36.5	+0.2
1H meso	3.63	3.58	3.26	3.18	−0.45
13C meso	35.7	35.5	36.9	36.9	+1.1
α-pyrrole 13C	53.9	54.1	44.8	41.9	−12.0
β-pyrrole 13Cd	158.9	157.4	151.0	146.7	−12.2
Met61 ε-C1H3	−15.27	−15.09	−17.69	−18.26	−2.99
His16 δ1-15Ne	182.3	181.3	170.5	167.1	−15
His16 δ1-N1He	13.2	12.6	11.8	11.2	−1.6

^aAverage chemical shifts are reported for heme nuclei.

^bTemperature is 40 °C except where noted otherwise.

^cThe change in chemical shift for the most ruffled Ht variant relative to Ht WT.

^dFour out of the eight β-pyrrole ¹³C shifts were averaged, according to the 4-¹³C-ALA labeling scheme (Figure 1a).

^eMeasured at 25 °C, from Michel et al.⁴⁵