THE TRANSLOCATION OF NEGATIVELY CHARGED RESIDUES ACROSS THE MEMBRANE IS DRIVEN BY THE ELECTROCHEMICAL POTENTIAL - EVIDENCE FOR AN ELECTROPHORESIS-LIKE MEMBRANE TRANSFER MECHANISM
THE TRANSLOCATION OF NEGATIVELY CHARGED RESIDUES ACROSS THE MEMBRANE IS DRIVEN BY THE ELECTROCHEMICAL POTENTIAL - EVIDENCE FOR AN ELECTROPHORESIS-LIKE MEMBRANE TRANSFER MECHANISM
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DOI：
10.1002/j.1460-2075.1995.tb07068.x
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发表时间：
1995-03-01
期刊：
影响因子：
11.4
通讯作者：
DALBEY, RE
中科院分区：
文献类型：
--
作者：
CAO, GQ;KUHN, A;DALBEY, RE
膜电化学电位的作用，在跨膜的酸性和碱性残基的易位进行了研究与M13前外壳蛋白，它有一个短的周质环，和前导肽酶，它有一个扩展的位于周质的N-末端尾巴。对于这两种蛋白质，我们发现，只有当带负电荷的残基存在于易位域的膜电位促进膜转移。当这些残基被不带电荷的氨基酸取代时，蛋白质独立于电位插入膜中。相反，当带正电荷的残基存在于前导肽酶的N-末端尾部内时，电位阻碍尾部结构域的移位。然而，在前壳蛋白的情况下，没有观察到障碍，其中带正电荷的残基在中央环易位，即使在膜电位的存在下。有趣的是，几种带负电荷的前外壳蛋白需要SecA和SecY蛋白进行最佳易位。这里报道的研究提供了深入了解膜蛋白组装的潜力的作用，并建议电泳可以发挥重要作用，在控制膜拓扑结构。
The role of the membrane electrochemical potential in the translocation of acidic and basic residues across the membrane was investigated with the M13 procoat protein, which has a short periplasmic loop, and leader peptidase, which has an extended periplasmically located N-terminal tail. For both proteins we find that the membrane potential promotes membrane transfer only when negatively charged residues are present within the translocated domain. When these residues are substituted by uncharged amino acids, the proteins insert into the membrane independently of the potential. In contrast, when a positively charged residue is present within the N-terminal tail of leader peptidase, the potential impedes translocation of the tail domain. However, an impediment was not observed in the case of the procoat protein, where positively charged residues in the central loop are translocated even in the presence of the membrane potential. Intriguingly, several of the negatively charged procoat proteins required the SecA and SecY proteins for optimal translocation. The studies reported here provide insights into the role of the potential in membrane protein assembly and suggest that electrophoresis can play an important role in controlling membrane topology.