紫色细菌沙氏外硫红螺菌中钠依赖性琥珀酸摄取

Sodium-dependent succinate uptake in purple bacterium Ectothiorhodospira shaposhnikovii.

作者信息

Karzanov V V, Ivanovsky R N

出版信息

Biochim Biophys Acta. 1980 May 8;598(1):91-9. doi: 10.1016/0005-2736(80)90267-9.

Abstract

Succinate, malate and fumarate uptake in purple sulfur bacterium Ectothiorhodospira shaposhnikovii,. strain 1 K MSU, obligatorily depends on the presence of Na+. Other monovalent cations such as K+, Li+, NH4+ could not replace Na+. Experiments with energy-depleted cells have shown that succinate uptake against its concentration gradient can be energized by artifically imposed sodium gradients (delta pNa). An artificial membrane potential (inside negative) inhibited delta pNa-driven succinate uptake at pH 7.0 but stimulated it at pH 9.0. The results confirm the suggestion that succinate uptake in E. shaposhnikovii is carried out in symport with Na+.

摘要

紫色硫细菌沙氏外硫红螺菌（Ectothiorhodospira shaposhnikovii）菌株1K MSU对琥珀酸、苹果酸和富马酸的摄取必然依赖于Na⁺的存在。其他单价阳离子如K⁺、Li⁺、NH₄⁺不能替代Na⁺。对能量耗尽细胞的实验表明，逆着其浓度梯度的琥珀酸摄取可以由人工施加的钠梯度（ΔpNa）提供能量。人工膜电位（内侧为负）在pH 7.0时抑制ΔpNa驱动的琥珀酸摄取，但在pH 9.0时刺激该摄取。结果证实了关于沙氏外硫红螺菌中琥珀酸摄取是与Na⁺协同运输进行的这一推测。