. Author manuscript; available in PMC: 2013 Jun 30.

Published in final edited form as: Nitric Oxide. 2012 Apr 18;27(1):32–39. doi: 10.1016/j.niox.2012.04.002

Table 1.

Comparison of initial nitrite reductase rates for HbA and Hb–HP. Conditions: 0.2 mM heme, 1:1.1 heme:nitrite; 0.05 M Bis–Tris, pH 7.0 + dithionite (>1:1 heme). Rates derived from changes in the 430 nm deoxy band monitored as a function of time. The rates for HbA and Hb–Hp are averages of two independent runs. The conditions for the oxygen affinity and cooperativity measurements are given in the text. The P₅₀ and n₅₀ (Hill coefficient) values for the crosslinked Hb are taken from an earlier work [48].

Sample	Rate (μM s⁻¹)	P₅₀ (mm Hg)	n₅₀
Hb–Hp	0.111 ± 0.001	4.79 ± 0.21	1.06 ± 0.081
Hb	0.022 ± 0.01	13.63 ± 0.11	2.38 ± 0.015
XL P2K Hb	0.087	6.5	2.1