Giglione C, Gross J D
Department of Biochemistry, University of Oxford, United Kingdom.
Biochem Mol Biol Int. 1995 Aug;36(5):1057-65.
Chloride ions stimulated the ATP-dependent formation of a proton gradient in vesicles derived from amoebae of the cellular slime mould, D. discoideum, and reduced the formation of a membrane potential, inhibited rather than stimulated the formation of the proton gradient. Since bicarbonate ions did not inhibit H(+)-ATPase activity we conclude that they enter the vesicles and combine with translocated protons. This finding is consistent with the suggestion that the membranes of the light vesicle fraction are fragments of contractile vacuole complexes, and that these organelles increase their osmotic activity by taking up bicarbonate ions and protons from the cytoplasm, and then release water and carbonic acid into the extracellular milieu.
氯离子刺激了源自细胞黏菌盘基网柄菌变形虫的囊泡中依赖ATP的质子梯度形成，并降低了膜电位的形成，抑制而非刺激了质子梯度的形成。由于碳酸氢根离子不抑制H(+)-ATP酶活性，我们得出结论，它们进入囊泡并与转运的质子结合。这一发现与以下观点一致：轻囊泡部分的膜是收缩泡复合体的片段，并且这些细胞器通过从细胞质中吸收碳酸氢根离子和质子来增加其渗透活性，然后将水和碳酸释放到细胞外环境中。
