Uncoupled eNOS favours the formation of superoxide

BH2 may compete with BH4 to bind eNOS, uncoupling eNOS leading to the formation of superoxide rather than nitric oxide. BH2, the oxidised form of BH4, cannot contribute electrons to heme in the reductase domain of eNOS, thereby uncoupling it from arginine oxidation and producing superoxide from oxygen instead (Vasquez-Vivar et al. 2002).

BH2可与BH4竞争结合eNOS，导致eNOS解偶联，从而生成超氧阴离子而非一氧化氮。BH2作为BH4的氧化形式，无法向eNOS还原酶域中的血红素提供电子，因此使其与精氨酸氧化解偶联，并从氧气中产生超氧阴离子（Vasquez-Vivar等，2002年）。