Opanasenko Vera, Agafonov Alexey, Demidova Raissa
Laboratory of Bioenergetics of Photosynthesis, Institute of Basic Biological Problems RAS, Pushchino, Moscow Region, 142290, Russia,
Photosynth Res. 2002;72(3):243-53. doi: 10.1023/A:1019830807554.
The effect of low concentrations (up to 50 muM) of lipophilic permeant amines on the electron transfer in thylakoid membranes of pea chloroplasts has been investigated. In the presence of heterocyclic amines (9-aminoacridine and neutral red), the electron transfer, initiated from H(2)O to PS I acceptors, has been shown to be inhibited to a level amounting to less than 50% of control, this taking place for both the basal (at alkaline pH) and the gramicidin-uncoupled transport (at pH 6.5-8.5). Under the same conditions, tertiary amines (dibucaine, tetracaine) cause only a 10-15% inhibition of transport. With all the amines, the rate of electron transport from H(2)O to DCBQ, PS II acceptor is decreased to 80-90% of control at pH above 8.0, but this effect is completely removed when pH is lowered to 7.7-6.5. In the region of PS I, all the amines accelerate the basal transport, but do not influence the uncoupled electron transfer. A conclusion has been drawn that, parallel with uncoupling, heterocyclic and tertiary amines also cause an inhibition of PS II, appearing at alkaline pH values. Additionally, heterocyclic amines seem to brake electron flow at the level of plastoquinone reduction.
研究了低浓度（高达50μM）的亲脂性渗透胺对豌豆叶绿体类囊体膜中电子传递的影响。在存在杂环胺（9-氨基吖啶和中性红）的情况下，从H₂O到PS I受体引发的电子传递已被证明受到抑制，抑制水平低于对照的50%，这在碱性pH下的基础转运以及短杆菌肽解偶联转运（在pH 6.5 - 8.5）中均会发生。在相同条件下，叔胺（丁卡因、丁哌卡因）仅导致10 - 15%的转运抑制。对于所有胺类，在pH高于8.0时，从H₂O到二氯酚靛酚（DCBQ，PS II受体）的电子传递速率降至对照的80 - 90%，但当pH降至7.7 - 6.5时，这种效应完全消除。在PS I区域，所有胺类都会加速基础转运，但不影响解偶联的电子传递。得出的结论是，与解偶联同时，杂环胺和叔胺在碱性pH值下也会导致PS II受到抑制。此外，杂环胺似乎在质体醌还原水平上抑制电子流动。
