. Author manuscript; available in PMC: 2018 Jun 14.

Published in final edited form as: J Am Chem Soc. 2017 Jun 6;139(23):7958–7973. doi: 10.1021/jacs.7b03292

Table 4. Overall Thermodynamics of O–O Bond Rupture in CcO for Different Combinations of Possible e⁻ Source with the Lowest Energy H⁺ Donor Available (Arg⁺) and Tyr^a.

{[(heme a) (His)Fe–O₂-Cu(His)₃]⁺} + {HA} + {E⁻} → {[(heme a) FeO(His)]⁺ + [(His)₃Cu(OH)]⁺} + {A⁻} + {E}

H⁺ donor ({HA})	e⁻ donor ({E⁻})	ΔG° (kcal/mol)
Arg⁺	Trp	+12.7
	TyrH	+17.2
	Tyr⁻	−35.9
Tyr	Trp	+44.0
	Tyr⁻	−4.6

Calculated in ε = 4.0 at 298 K. Note that a carboxylic acid H⁺ donor yields a ΔG° in between the values obtained for Arg⁺ and Tyr. Independently calculated components are denoted by braces.

Table 4. Overall Thermodynamics of O–O Bond Rupture in CcO for Different Combinations of Possible e− Source with the Lowest Energy H+ Donor Available (Arg+) and Tyra.

Table 4. Overall Thermodynamics of O–O Bond Rupture in CcO for Different Combinations of Possible e⁻ Source with the Lowest Energy H⁺ Donor Available (Arg⁺) and Tyr^a.