Table 2. Properties of catalysts based on re-purposed protein for catalytic production of H₂ from aqueous solution ^a .

Catalyst center b	Protein host	Electron supply/conditions	TON c	TOF c (h–1)	Ref.
NiS4 d	Rubredoxin (Rd)	Reduced MV/KPi, pH 6.8, 32 °C	—	594 ± 54 e	125
NiS4 d	Rubredoxin (Rd)	1 mM PS, 0.1 M NaAsc/KPi, pH 6.5, 4 °C	32 (1 h)	30 (ini)	126
CoP, 1 (His93)	Myoglobin	1 mM PS, 0.1 M NaAsc/KPi, pH 7	518 (12 h)	88	127
CoP, 1(His107)	Cyt b562 (Met7Ala mutant)	1 mM PS, 0.1 M NaAsc/KPi, pH 7	310 (8 h)	—	128
2 (His93)	SwMb	20 eq. PS, 0.1 M NaAsc/KPi NaCl (150 mmol L–1), pH 6	3.8 f (5 min)	—	130
3 (His25)	Rat heme oxygenase	15 eq. [Eu(EGTA) (H2O)]2–/Tris–HCl, pH 7	6.2 f (5 min)	—	134
2 (His90)	S. oleracea ferredoxin	PS derivate, g 0.1 M NaAsc/MES, pH 6.3	210 h ± 60 (6 h)	60 h (ini)	137
2	S. lividus apo-flavodoxin	PS derivate, g 0.1 M NaAsc/MES, pH 6.3	85 h ± 35 (6 h)	30 h ± 10 (ini)	138
6	S. lividus apo-flavodoxin	PS derivate, g 0.1 M NaAsc/MES, pH 6.2	620 ± 80 (4 h)	410 ± 30 (ini)	140
[(μ-S2) Fe2(CO)6] motif (Cys14, Cys17)	Equine heart apo-cyt c	10 eq. PS, 0.1 M NaAsc/Tris–HCl, pH 4.7	80 (2 h)	126 (ini)	141
7 (Cys96)	Apo-NB (Gln96Cys mutant)	PS, 0.1, M NaAsc/Tris–HCl, pH 4.0	130 (6 h)	136 (ini)	142

^aMV = methyl viologen, PS = [Ru(bpy)₃]²⁺, and NaAsc = sodium ascorbate.

^bIn parentheses are the amino acids from the protein host involved in the metal binding.

^cIn parentheses is the duration of the experiment used to determine the corresponding value.

^dDirect coordination by four Cys from the protein.

^enmol per s^–1 per mg Rd.

^fTON is calculated vs. the number of introduced cobalt centers.

^gPS covalently bound to the protein.

^hTONs and TOFs are calculated vs. the number of photosensitizers.