Department of Biology, Brandeis University, Waltham, Massachusetts 02154.
Plant Physiol. 1971 Oct;48(4):443-6. doi: 10.1104/pp.48.4.443.
Low concentrations (0.5-10 mum) of antimycin A were shown to increase the rate of CO(2) fixation, O(2) evolution and inorganic phosphate esterification in intact spinach (Spinacia oleracea) chloroplasts. The increase was highest when the light intensity was saturating. Stimulation was independent of the bicarbonate concentration and was accompanied by an enhancement in the synthesis of glycerate 3-phosphate with a decrease in dihydroxyacetone phosphate. The antibiotic decreased the Michaelis constant of the chloroplast but not of ribulose 1,5-diphosphate carboxylase for bicarbonate. It was suggested that antimycin A is affecting that portion (outer envelope) of the intact chloroplast which contains the enzyme mechanism for controlling the pace of CO(2) fixation.
低浓度(0.5-10 µm)的抗霉素 A 被证明可以提高完整菠菜(Spinacia oleracea)叶绿体中 CO2 固定、O2 释放和无机磷酸盐酯化的速率。当光强度达到饱和时,增加幅度最大。这种刺激与重碳酸盐浓度无关,伴随着甘油酸 3-磷酸合成的增强和二羟丙酮磷酸的减少。抗生素降低了叶绿体的米氏常数,但对核酮糖 1,5-二磷酸羧化酶对重碳酸盐的米氏常数没有影响。因此,抗霉素 A 可能影响完整叶绿体的那个部分(外被),其中包含控制 CO2 固定速度的酶机制。