Table 1. Summary of the results from the electrochemical analysis. All potentials reported were measured against the Ag/AgCl electrode.

	PySSCou	Cys	DTT	GSH	Hcy
Eox [V]	−0.590	−0.869	0.360	−0.565	−0.589
Ered [V]	−1.010	−1.080	−3.690	−1.050	−1.030
Eo1/2 [V]	−0.805	−0.975	−1.665	−0.808	−0.810
EoCell [a] [V]	0	0.170	0.860	0.003	0.005
ΔGo [b] [J/mol]	0	−2900	−15000	−51	−87

a) Difference between the standard reduction potentials (E^o_1/2) of PySSCou and respective thiol compounds. b) Estimated Gibbs free energy based on ΔG^o = -nFE^o_cell, where n is the number of electrons involved (2 electrons for disulfide exchange reaction) and F is Faraday's constant.