TABLE 1.

Time constants of proton uptake and release and proton stoichiometries

Time constants of proton uptake and release as well as of electron transfer in the O → E step and proton stoichiometries for the individual proton transfer reactions triggered by the injection of 1 electron into the oxidized enzyme are given below.

	H+ uptake τ1	H+ release		Net proton uptake	e− transfer
		τ2	τ3		τ1	τ2
	μs	μs			μs
Solubilized COX	1.2 ± 0.1	11.5 ± 2.8	249 ± 18		1.5 ± 0.1	13.2 ± 0.7
COX-containing liposomes	0.9 ± 0.1	6.7 ± 1.4	192 ± 28		2.7 ± 0.2	13.6 ± 2.9
H+/COX
Solubilized COX	2.6 ± 0.4	0.8 ± 0.2	1.4 ± 0.2	0.38 ± 0.05
COX-containing liposomes (detection at P-side)	1.6 ± 0.4	1.1 ± 0.2	0.5 ± 0.2	0
Solubilized D124N	1.0 ± 0.2	0.5 ± 0.08	0.4 ± 0.06	0.1 ± 0.02
Solubilized K354M	1.3 ± 0.2	0.7 ± 0.1	0.2 ± 0.03	0.2 ± 0.03