Table 1.

Reduction Potentials of Horse Heart Cytochrome c Variants^a

Variant	pH	Axial ligand	E° (mV vs SHE)
WT	7.8	Met	255b
	10.0	Lys	−205c
T49V	4.5	Met (major)	144 ± 5 (240 ± 5)d
		H2O (minor)
	7.4	Lys (major)	−15 ± 8 (−15 ± 8)
		Met (minor)
Y67R/M80A	4.5	H2O	−54 ± 7 (−22 ± 3)
	7.4	Lys	−80 ± 7 (−56 ± 1)
M80A	4.5	H2O	16 ± 6 (32 ± 3)
	7.4	OH−	−33 ± 4 (–)
	7.0		185e

^aIn this work, potentials were determined from spectroelectrochemistry experiments performed at 22 ± 2 °C.

^bFrom ref. 55.

^cFrom ref. 56.

^dReductive (oxidative) direction.

^eFrom ref. 52.