Cytochrome b-245 heavy chain (CYBB)

Critical part of the membrane-bound oxidase of phagocytes that generates superoxide. It's the terminal part of a respiratory chain that transports single electrons from cytoplasmic NADPH throughout the plasma membrane to molecular oxygen on the exterior.

Also functions as a voltage-gated proton channel that mediates the H(+) currents of resting phagocytes. It participates in the regulation of cellular pH and is blocked by zinc.