Meins Thomas, Vonrhein Clemens, Zeth Kornelius
Max Planck Institute of Biochemistry, Department of Membrane Biochemistry, Am Klopferspitz 18, D-82152 Martinsried, Germany.
Acta Crystallogr Sect F Struct Biol Cryst Commun. 2008 Jul 1;64(Pt 7):651-5. doi: 10.1107/S174430910801676X. Epub 2008 Jun 28.
The major channel by which metabolites can pass through the outer mitochondrial membrane is formed by the voltage-dependent anion-channel (VDAC) family. Functionally, VDAC is involved in the limited exchange of ATP, ADP and small hydrophilic molecules across the outer membrane. Moreover, there is compelling evidence that VDAC isoforms in mammals may act in the cross-talk between mitochondria and the cytoplasm by direct interaction with enzymes involved in energy metabolism and proteins involved in mitochondrial-induced apoptosis. To obtain a high-resolution structure of this channel, human VDAC protein isoform I was overproduced in Escherichia coli. After refolding and testing the correct fold using circular dichroism, a subsequent broad-range screening in different detergents resulted in a variety of crystals which diffracted to 3.5 A resolution. The crystal lattice belongs to the trigonal space group P321, with unit-cell parameters a = 78.9, c = 165.7 A and one monomer in the asymmetric unit.
代谢物穿过线粒体外膜的主要通道是由电压依赖性阴离子通道（VDAC）家族形成的。在功能上，VDAC参与ATP、ADP和小的亲水分子在外膜上的有限交换。此外，有令人信服的证据表明，哺乳动物中的VDAC同工型可能通过与参与能量代谢的酶和参与线粒体诱导凋亡的蛋白质直接相互作用，在线粒体与细胞质之间的串扰中发挥作用。为了获得该通道的高分辨率结构，人VDAC蛋白同工型I在大肠杆菌中过量表达。在使用圆二色性对正确折叠进行重折叠和测试后，随后在不同去污剂中进行的广泛筛选产生了多种晶体，其衍射分辨率达到3.5 Å。晶格属于三方空间群P321，晶胞参数a = 78.9，c = 165.7 Å，不对称单元中有一个单体。
