Phospholipid-assisted refolding of an integral membrane protein - Minimum structural features for phosphatidylethanolamine to act as a molecular chaperone
Phospholipid-assisted refolding of an integral membrane protein - Minimum structural features for phosphatidylethanolamine to act as a molecular chaperone
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DOI：
10.1074/jbc.274.18.12339
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发表时间：
1999-04-30
影响因子：
4.8
通讯作者：
Dowhan, W
中科院分区：
文献类型：
--
作者：
Bogdanov, M;Umeda, M;Dowhan, W
大肠杆菌来源的磷脂酰乙醇胺(PE)或含有完全饱和脂肪酸的PE能够在体外纠正在没有PE的情况下体内组装导致的乳糖渗透酶(Lacy)的脂依赖表位4B1的折叠缺陷。PE血浆蛋白原、含有两种不饱和脂肪酸的PE和Lyso-PE都不支持正确的复性，当这些后者的脂类与单独不支持复性的双层形成脂(磷脂酰甘油)混合时发生适当的复性，而L-磷脂酰丝氨酸(PS；天然非对映异构体)支持适当的复性，随着甲基化程度的增加，PE的衍生物对复性的支持作用逐渐减弱，而磷脂酰胆碱完全无效。因此，能够组织成双层结构的非甲基化氨基磷脂的性质对于在体内错误组装后4B1表位的自然状态的恢复是必不可少的。在没有PE的情况下，D-PS(sn-甘油-L-磷酸骨架)和P-D-S(头基为D-丝氨酸)都不能支持正确的复性，除非用于与磷脂酰甘油的二元混合物中。本文报道的磷脂辅助复性的详细特征进一步支持了PE在体内乳糖渗透酶结构成熟中的特定作用而不是非特定作用(Bogdanov，RI.和Dowhan，W，(1998)EMBO J，17,5255-5264)。
Escherichia coli-derived phosphatidylethanolamine (PE) or PE with fully saturated fatty acids was able to correct in vitro a defect in folding in the lipid dependent epitope 4B1 of lactose permease (LacY) resulting from in vivo assembly in the absence of PE. PE plasmalogen, PE with two unsaturated fatty acids, and lyso-PE, which all do not favor bilayer organization, did not support proper refolding, Proper refolding occurred when these latter lipids were mixed with a bilayer-forming lipid (phosphatidylglycerol), which alone could not support refolding, L-Phosphatidylserine (PS; natural diastereomer) did support proper refolding, PE derivatives of increasing degrees of methylation were progressively less effective in supporting refolding, with phosphatidylcholine being completely ineffective. Therefore, the properties of nonmethylated aminophospholipids capable of organization into a bilayer configuration are essential for the recovery of the native state of epitope 4B1 after misassembly in vivo in the absence of PE, Neither D-PS (sn-glycero-l-phosphate backbone) nor P-D-S (D-serine in the head group) is competent in supporting proper refolding unless used in binary mixtures with phosphatidylglycerol. The detailed characterization of phospholipid-assisted refolding reported here further supports a specific rather than nonspecific role for PE in structural maturation of lactose permease in vivo (Bogdanov, RI., and Dowhan, W, (1998) EMBO J, 17, 5255-5264).