Department of Biology, Applied Plant Sciences, Technische Universität Darmstadt, Schnittspahnstrasse 10, D-64287 Darmstadt, Germany.
Sci Rep. 2012;2:538. doi: 10.1038/srep00538. Epub 2012 Jul 27.
We demonstrate that membranes consisting of certain triblock-copolymers were tight for CO₂. Using a novel approach, we provide evidence for aquaporin facilitated CO₂ diffusion. Plant aquaporins obtained from heterologous expression were inserted into triblock copolymer membranes. These were employed to separate a chamber with a solution maintaining high CO₂ concentrations from one with depleted CO₂ concentrations. CO₂ diffusion was detected by measuring the pH change resulting from membrane CO₂ diffusion from one chamber to the other. An up to 21 fold increase in diffusion rate was determined. Besides the supply of this proof of principle, we could provide additional arguments in favour of protein facilitated CO₂ diffusion to the vivid on-going debate about the principles of membrane gas diffusion in living cells.
我们证明了由某些三嵌段共聚物组成的膜对 CO₂具有高选择性。我们采用一种新方法，为水通道蛋白促进 CO₂扩散提供了证据。从异源表达中获得的植物水通道蛋白被插入到三嵌段共聚物膜中。这些膜被用于将一个保持高 CO₂浓度的溶液的腔室与一个 CO₂浓度耗尽的腔室隔开。通过测量由于膜 CO₂从一个腔室扩散到另一个腔室而导致的 pH 值变化来检测 CO₂扩散。确定扩散速率提高了 21 倍。除了提供这个原理的证明之外，我们还可以为蛋白质促进 CO₂扩散提供更多的论据，以支持关于活细胞中膜气体扩散原理的激烈争论。
