Journet E P, Bligny R, Douce R
Biochem J. 1986 Jan 15;233(2):571-6. doi: 10.1042/bj2330571.
Protoplasts obtained from sycamore (Acer pseudoplatanus) cell suspensions were found to be highly intact and to retain a high rate of O2 consumption. If the protoplasts were taken up and expelled through a fine nylon mesh, all the protoplasts were ruptured, leaving the fragile amyloplasts largely intact. Distribution of enzymes of glycolysis in plastids and soluble phase of sycamore protoplasts indicated that the absolute maximum activity for each glycolytic enzyme under optimum conditions exceeded the estimates of the maximal rate at which sycamore cells oxidize triose phosphate. Passage of protoplasts through the fine nylon mesh produced a 3-5-fold decrease in O2 consumption. However, addition of saturating amounts of respiratory substrates and ADP restored an O2 consumption equal to that observed with uncoupled intact protoplasts. Taken together, these results demonstrated that neither the overall capacity of the glycolytic enzymes in sycamore cells nor the availability of respiratory substrates for the mitochondria is ultimately responsible for determining the rate of uncoupled respiration in sycamore cells.
从悬铃木（Acer pseudoplatanus）细胞悬浮液中获得的原生质体被发现具有高度完整性，并保持较高的耗氧率。如果将原生质体通过细尼龙网吸入和挤出，所有原生质体都会破裂，而脆弱的造粉体在很大程度上保持完整。悬铃木原生质体的质体和可溶性相中糖酵解酶的分布表明，在最佳条件下，每种糖酵解酶的绝对最大活性超过了悬铃木细胞氧化磷酸丙糖的最大速率估计值。原生质体通过细尼龙网后，耗氧量降低了3至5倍。然而，添加饱和量的呼吸底物和ADP可使耗氧量恢复到与未偶联的完整原生质体所观察到的相同水平。综合来看，这些结果表明，悬铃木细胞中糖酵解酶的总体能力以及线粒体呼吸底物的可用性都不是最终决定悬铃木细胞未偶联呼吸速率的原因。
