Cytochrome b5 reductase
Cytochrome-b5 reductase is a NADH-dependent enzyme that converts methemoglobin to hemoglobin. It contains FAD and catalyzes the reaction:
NADH + H+ + 2 ferricytochrome b5 = NAD+ + 2 ferrocytochrome b5
The following four human genes encode cytochrome-b5 reductases:
