Kucera I, Laucík J, Dadák V
Eur J Biochem. 1983 Oct 17;136(1):135-40. doi: 10.1111/j.1432-1033.1983.tb07716.x.
The rate of reduction of terminal acceptors (nitrate, nitrite, and oxygen) in anaerobically grown cells of Paracoccus denitrificans increased on permeabilization of cytoplasmic membrane. It was proved that under aerobic conditions the increase of the rate of nitrate reduction was caused by: (i) the abolishment of the permeability barrier for nitrate, (ii) the enhancement of the influx of redox equivalents to the respiratory chain due to the stimulation of succinate dehydrogenase reaction, and (iii) the inhibition of electron flow to oxygen by endogenously formed nitrite. Nitrite inhibits oxygen reduction by its interaction with the terminal part of the respiratory chain (I50 = 15 microM) localized at the inner aspect of the cytoplasmic membrane. The distribution of nitrite between intact cells and the suspension medium follows the Nernst equation for monovalent anion. The possible physiological consequences of the low intracellular nitrite concentration are discussed.
在反硝化副球菌厌氧生长的细胞中，细胞质膜通透后，末端受体（硝酸盐、亚硝酸盐和氧气）的还原速率增加。已证明，在有氧条件下，硝酸盐还原速率的增加是由以下原因引起的：（i）硝酸盐通透屏障的消除；（ii）由于琥珀酸脱氢酶反应的刺激，氧化还原当量向呼吸链的流入增强；（iii）内源性形成的亚硝酸盐对电子流向氧气的抑制。亚硝酸盐通过与位于细胞质膜内侧的呼吸链末端部分相互作用（I50 = 15 microM）来抑制氧气还原。完整细胞与悬浮培养基之间亚硝酸盐的分布遵循单价阴离子的能斯特方程。讨论了细胞内亚硝酸盐浓度低可能产生的生理后果。
