Table 3.

Nitrite reductase rates of selected wild-type globins and mutants.

Protein	Protein	Reaction rate constant (M−1s−1)	Reference
Myoglobin	WT	5.6 ± 0.6b	[15]
	H64A	1.8 ± 0.3b	[15]
	F43H	1.4 ± 0.1c	[35]
	F43H/H64A	49.8 ± 1.5c	[35]
Neuroglobin	WT	0.52 ± 0.19 d	[19]
	H64A	1120 ± 140 d	[19]
	F28H	0.37 ± 0.05	[19]
	F42Y	0.071 ± 0.006	This work
	F28H/F42Y	0.184 ± 0.043	This work

Reaction rate constants for wt Ngb and mutants determined at 37 °C in 100 mM sodium phosphate, pH 7.4. Rate constants for Mb determined at 25 °C in 100 mM sodium phosphate [15] or 100 mM potassium phosphate [35].