Bay Denice C, Court Deborah A
Department of Microbiology, University of Manitoba, Winnipeg, Canada.
Biochem Cell Biol. 2002;80(5):551-62. doi: 10.1139/o02-149.
Voltage-dependent anion-selective channels (VDAC), also known as mitochondrial porins, are key regulators of metabolite flow across the mitochondrial outer membrane. Porins from a wide variety of organisms share remarkably similar electrophysiological properties, in spite of considerable sequence dissimilarity, indicating that they share a common structure. Based on primary sequence considerations, analogy with bacterial porins, and circular dichroism analysis, it is agreed that VDAC spans the outer membrane as a beta-barrel. However, the residues that form the antiparallel beta-strands comprising this barrel remain unknown. Various predictive methods, largely based on the known structures of bacterial beta-barrels, have been applied to the primary sequences of VDAC. Refinement and confirmation of these predictions have developed through numerous investigations of wild-type and variant porins, both in mitochondria and in artificial membranes. These experiments have involved VDAC from several sources, precluding the generation of a unified model. Herein, using the Neurospora VDAC sequence as a template, the published structural information and predictions have been reassessed to delineate a model that satisfies most of the available data.
电压依赖性阴离子选择性通道（VDAC），也被称为线粒体孔蛋白，是跨线粒体外膜代谢物流动的关键调节因子。尽管各种生物来源的孔蛋白序列差异很大，但它们具有非常相似的电生理特性，这表明它们具有共同的结构。基于一级序列的考量、与细菌孔蛋白的类比以及圆二色性分析，人们一致认为VDAC以β-桶状结构跨线粒体外膜。然而，构成该桶状结构的反平行β-链的残基仍然未知。各种主要基于细菌β-桶状结构已知结构的预测方法已应用于VDAC的一级序列。通过对线粒体和人工膜中的野生型和变体孔蛋白的大量研究，这些预测得到了完善和证实。这些实验涉及多种来源的VDAC，因此无法生成一个统一的模型。在此，以粗糙脉孢菌VDAC序列为模板，重新评估已发表的结构信息和预测结果，以描绘出一个符合大多数现有数据的模型。
