Table 4. Distal Histidine Binding Constants, Nitrite Reductase Rate Constants, and Redox Potentials for Selected Globinsa.
| distal
histidine binding |
|||||
|---|---|---|---|---|---|
| protein | kbinding (s–1) | kdissoc (s–1) | KHis | KNitrite (M–1 s–1) | Em (mV) |
| Ngb (human) | 2000b | 4.5b | 444b | 0.12c | –118d |
| Cgb (human) | 200e | 2e | 100e | 0.14f | –28g |
| SynHb | 4200h | 14h | 300h | 27i | –195g |
| RHb1 | 75h | 40h | 1.9h | 40i | –143g |
| AtHb1 | 230j | 110j | 2.1j | 19.8k | NDm |
| AtHb2 | 1600j | 38j | 42j | 4.9k | NDm |
| SwMb | NAn | NAn | NAn | 5.6c | –59l |
a
Histidine dissociation determined at 20 °C in 100 mM sodium phosphate buffer (pH 7.0). Nitrite reductase rates determined at 25 °C in 100 mM sodium phosphate buffer (pH 7.4), except for those Cgb, SynHb, and RHb1, which were determined at pH 7.0. All redox potentials determined at 25 °C in 100 mM sodium phosphate buffer (pH 7.0).
b
From ref (26).
c
From ref (4).
d
From this work.
e
From ref (45).
f
From ref (4).
g
From ref (21).
h
From ref (46).
i
From ref (16).
j
From ref (47).
k
From ref (15).
l
From ref (31).
m
Not determined.
n
Not applicable.