Table 1.

Autoxidation, chemical oxidation, and heme loss kinetics for hemoglobin S mutants

	Autoxidation rate	Heme loss rate		koxida	[sulfHb]b at 30 min	Ferryl reductionc
		k1	k2			Autoreduction, kauto	50 μm ascorbate, k1	50 μm ascorbate, k2
	h−1	h−1		min−1	μm	min−1
HbA	0.040 ± 0.002	9.0 ± 1.3	1.0 ± 0.1	0.13 ± 0.01	14.3 ± 0.3	0.052 ± 0.001d	0.359 ± 0.007	0.032 ± 0.001
Native HbS	0.047 ± 0.002	15.5 ± 1.9	1.7 ± 0.3	0.14 ± 0.01	14.1 ± 0.2	0.048 ± 0.001	0.326 ± 0.006	0.022 ± 0.001
rHbS	0.069 ± 0.003	12.4 ± 1.1	2.1 ± 0.1	0.18 ± 0.01	16.1 ± 0.5	0.046 ± 0.001	0.319 ± 0.023	0.021 ± 0.000
rHbS βF41Y	0.067 ± 0.002	14.0 ± 1.3	3.3 ± 0.2	0.19 ± 0.01	9.5 ± 0.2	0.058 ± 0.001	0.426 ± 0.033	0.045 ± 0.001
rHbS βK82D	0.075 ± 0.006	16.1 ± 0.8	2.5 ± 0.2	0.24 ± 0.01	16.2 ± 0.4	0.051 ± 0.001	0.311 ± 0.028	0.014 ± 0.001
rHbS βF41Y/K82D	0.080 ± 0.004	9.8 ± 0.5	3.8 ± 0.4	0.24 ± 0.01	9.2 ± 0.3	0.057 ± 0.001	0.455 ± 0.043	0.032 ± 0.001

^a Data were calculated from Fig. 5, 60 μm Hb + 60 μm H₂O₂ with a spectrophotometer.

^b Data were calculated from Fig. 6B.

^c Data were calculated from Fig. 7. 5 μm ferryl Hb reacted with 0 or 50 μm ascorbate in PBS at room temperature.

^d Initial autoreduction rate is shown.