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. Author manuscript; available in PMC: 2011 Mar 1.
Published in final edited form as: Proteins. 2010 Mar;78(4):917–931. doi: 10.1002/prot.22617

Table III.

Kinetic parameters for the binding of NO and CO to nitrobindin compared to sperm whale myoglobin, leghemoglobin, and nitrophorins 1–4.

Protein k’CO(µM−1 s−1) kCO(s−1) KCO(µM−1)

Nitrobindin (Fe2+) A 0.23 0.050 4.5
SWMb WT(Fe2+) B 0.53 0.019 28
SWMb H64Q(Fe2+) B 0.94 0.012 78
SWMb H64L (Fe2+) B 26 0.024 1,100
Soybean Lba(Fe2+) C 17 0.0078 2,200
Nitrophorin 4 pH 8.0 D 7.9 n.d. n.d.


Protein k’NO(µM−1 s−1) kNO(s−1) KNO(µM–1)

Nitrobindin (Fe2+) A 81 ~0.08 ~1,000
SWMb WT (Fe2+) B 22 0.000098 220,000
SWMb H64Q (Fe2+) B 43 0.00011 370,000
SWMb H64L (Fe2+) B 190 0.00013 1,500,000
Soybean Lb a (Fe2+) C 170 0.00002 9,000,000
Nitrobindin (Fe3+) A 1.2 73 0.016
metSWMb WT (Fe3+) B 0.080 12 0.0067
SW metMb H64Q (Fe3+) B 11 59 0.19
SW metMb H64L (Fe3+) B 44 80 0.55
Soybean metLba(Fe3+) E 0.14 3.0 0.047
Nitrophorin 1 pH 8.0 F 1.5 4.3 0.34
Nitrophorin 2 pH 8.0 F 33 32 1.0
Nitrophorin 3 pH 8.0 F 6.7 30 0.22
Nitrophorin 4 pH 8.0 F 2.5 15 0.17
A

Rate constants that were determined in this study were measured in 100 mM potassium phosphate buffer at pH 7 containing EDTA (1 mM) at 20 °C.

B

The rates were taken from Rohlfs et al. [35], Eich et al. [76], Thorsteinsson et al. [55], Foley [36].

C

Taken from Hargrove et al. [75].

D

Rates taken from Maes et al. [48]

E

Taken from Herold et al. [77]

F

Rates for the first step of NO binding to ferric forms of nitrophorins from Rhodinus prolixus,taken from Andersen et al. [47] and Maes et al. [71]. n.d., Not determined.