As it forms water-filled channel in the mitochondria outer membrane and diffuses essential metabolites such as NADH and ATP, the voltage-dependent anion channel (VDAC) protein family plays a central role in all eukaryotic cells. In comparison with their mammalian homologues, little is known about the structural and functional properties of plant VDACs. In the present contribution, one of the two VDACs isoforms of Solanum tuberosum, stVDAC36, has been successfully overexpressed and refolded by an in-house method, as demonstrated by the information on its secondary and tertiary structure gathered from circular dichroism and intrinsic fluorescence. Cross-linking and molecular modeling studies have evidenced the presence of dimers and tetramers, and they suggest the formation of an intermolecular disulfide bond between two stVDAC36 monomers. The pore-forming activity was also assessed by liposome swelling assays, indicating a typical pore diameter between 2.0 and 2.7 nm. Finally, insights about the ATP binding inside the pore are given by docking studies and electrostatic calculations.

中文翻译：

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马铃薯VDAC36的结构和功能表征。

电压依赖性阴离子通道（VDAC）蛋白家族在线粒体外膜中形成充满水的通道并扩散诸如NADH和ATP等基本代谢产物时，在所有真核细胞中都起着核心作用。与它们的哺乳动物同系物相比，关于植物VDAC的结构和功能特性知之甚少。在目前的贡献中，马铃薯的两个VDAC同工型之一stVDAC36已通过内部方法成功过表达并重新折叠，这是从圆二色性和固有荧光中收集到的有关其二级和三级结构的信息所证实的。交联和分子建模研究已证明存在二聚体和四聚体，并且它们表明两个stVDAC36单体之间形成了分子间二硫键。还通过脂质体溶胀测定法评估了成孔活性，表明典型的孔径在2.0至2.7nm之间。最后，通过对接研究和静电计算得出有关孔内ATP结合的见解。