Table 2.

Summary of kinetic parameters for roGFP1-R mutants

Variant	ka (DTT, high salt, min−1)	kb (DTT, low salt, min−1)	kc (H2O2, low salt, min−1)	Eo′ (DTT, V)d
roGFP1	0.13	0.11	0.42	− 0.281e
R1	0.16	0.19	0.89	− 0.269
R3	0.15	0.19	0.75	− 0.282
R7	0.19	0.28	1.41	− 0.268
R8	0.10	0.09	0.24	− 0.284
R9	0.17	0.18	0.59	− 0.278
R10	0.12	0.11	0.67	− 0.284
R11	0.22	0.32	0.55	− 0.275
R12	0.29	0.66	2.05	− 0.265
R14	0.31	0.56	1.22	− 0.263

^a Pseudo first-order reduction rate constants (k) determined at high ionic strength (300 mM NaCl, 50 mM HEPES), using 1 mM DTT.

^b Pseudo first-order reduction rate constants (k) determined at low ionic strength (0 mM NaCl, 50 mM HEPES), using 1 mM DTT.

^c Pseudo first-order oxidation rate constants (k) determined at low ionic strength (0 mM NaCl, 50 mM HEPES), using 1 mM H₂O₂ .

^d Midpoint potentials from titration against DTT (assumed E^o′, −323 mV) at 25° and pH 7. Average estimated error for the measurements is ± 0.0011 V.

^e This measurement was repeated by titration against lipoic acid (assumed E^o′, −290 mV) at 25° and pH 7, and was found to be −285 mV.