Table I.

Rate (k′) and equilibrium constants (K) for the reaction of oxygen and CO for some representative plant hemoglobins

Proteink′O2kO2KO2k′COkCOKCO
μm −1s−1 s−1 μm −1 μm −1s−1 s−1 μm −1
Nonsymbiotic Hbs-a
 Rice wild-type Hb1680.0381800720.0017200
 Rice Hb1-H77L62051121500.00275,000
 Barley Hb2.40.028860.210.0016131
Arabidopsis Hb1740.126171.50.00121250
Arabidopsis Hb210.1470.250.0013192
Symbiotic Hbs-b
 Soybean Lba1305.623160.00841900
 Lba-H16L4002.4161700.002471,000