Secondary structure, orientation, oligomerization, and lipid interactions of the transmembrane domain of influenza hemagglutinin.
Secondary structure, orientation, oligomerization, and lipid interactions of the transmembrane domain of influenza hemagglutinin.
复制标题
流感血凝素跨膜结构域的二级结构、方向、寡聚化和脂质相互作用。
作者：
Tatulian,SA;Tamm,LK
流感病毒血凝素（HA）是介导病毒膜与细胞膜融合的病毒包膜糖蛋白，是三个亚基的同源三聚体，每个亚基含有两个二硫键连接的多肽链，HA 1和HA 2。每个HA 2链跨越病毒膜，在其C-末端附近有一个假定的跨膜α-螺旋。重组HA的融合实验表明，该序列是膜融合的后期步骤所需的，因为HA的糖基磷脂酰肌醇锚定类似物仅介导膜的“半融合”，即，两个并列脂质双层的近端小叶而非远端小叶的合并[肯布尔et al.（1994）Cell 76，383−391]。为了从结构上解释HA 2跨膜结构域在膜融合中的功能，我们用圆二色谱、衰减全反射傅里叶变换红外光谱和凝胶电泳研究了X：31 HA（TMX 31）跨膜结构域合成肽的二级结构、取向、寡聚化和脂质相互作用。该肽在洗涤剂胶束和磷脂双层中主要是α-螺旋。与纯磷脂酰胆碱双层相比，由酸性脂质组成的脂质双层的螺旋度增加。在平面脂质双层，螺旋取向接近膜正常。TMX 31在SDS胶束中聚集成由2 ~ 5个亚基组成的小的耐热寡聚体。酰胺氢交换实验表明，很大一部分的螺旋残基可接近水，这表明TMX 31在脂质双层中形成孔的可能性。最后，肽增加了脂双层中的酰基链顺序，这可能与HA与细胞表面的脂“筏”的优先关联有关，并且这可能是完全膜融合的重要先决条件。
Influenza virus hemagglutinin (HA), the viral envelope glycoprotein that mediates fusion between the viral and cellular membranes, is a homotrimer of three subunits, each containing two disulfide-linked polypeptide chains, HA1and HA2. Each HA2chain spans the viral membrane with a single putative transmembrane α-helix near its C-terminus. Fusion experiments with recombinant HAs suggest that this sequence is required for a late step of membrane fusion, as a glycosylphosphatidylinositol-anchored analogue of HA only mediates “hemifusion” of membranes, i.e., the merging of the proximal, but not distal, leaflets of the two juxtaposed lipid bilayers [Kemble et al. (1994)Cell 76, 383−391]. To find a structural explanation for the function of the transmembrane domain of HA2in membrane fusion, we have studied the secondary structure, orientation, oligomerization, and lipid interactions of a synthetic peptide representing the transmembrane segment of X:31 HA (TMX31) by circular dichroism and attenuated total reflection Fourier transform infrared spectroscopy and by gel electrophoresis. The peptide was predominantly α-helical in detergent micelles and in phospholipid bilayers. The helicity was increased in lipid bilayers composed of acidic lipids compared to pure phosphatidylcholine bilayers. In planar lipid bilayers, the helices were oriented close to the membrane normal. TMX31 aggregated into small heat-resistant oligomers composed of two to five subunits in SDS micelles. Amide hydrogen exchange experiments indicated that a large fraction of the helical residues were accessible to water, suggesting the possibility that TMX31 forms pores in lipid bilayers. Finally, the peptide increased the acyl chain order in lipid bilayers, which may be related to the preferential association of HA with lipid “rafts” in the cell surface and which may be an important prerequisite for complete membrane fusion.
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影响因子：
3.4
作者：
Mario J. Citra;P. Axelsen
通讯作者：
Mario J. Citra;P. Axelsen
DOI：
10.1016/s0021-9258(18)48270-1
发表时间：
1987-05
期刊：
The Journal of biological chemistry
影响因子：
--
作者：
J. D. Lear;W. DeGrado
通讯作者：
J. D. Lear;W. DeGrado
傅里叶变换红外光谱和定点同位素标记作为受磷蛋白跨膜域局部二级结构的探针。
影响因子：
3.4
作者：
Ludlam,CF;Arkin,IT;Liu,XM;Rothman,MS;Rath,P;Aimoto,S;Smith,SO;Engelman,DM;Rothschild,KJ
通讯作者：
Rothschild,KJ
膜融合过程中融合病毒包膜蛋白形成的孔的第一毫秒。
DOI：
10.1073/pnas.88.9.3623
发表时间：
1991
影响因子：
11.1
作者：
Spruce,AE;Iwata,A;Almers,W
通讯作者：
Almers,W
揭示阿拉甲辛对心脏肌膜囊泡的 (Na ,K )-ATP 酶、β-肾上腺素受体偶联腺苷酸环化酶和 cAMP 依赖性蛋白激酶活性的影响。
影响因子：
4.8
作者：
L. Jones;S. Maddock;H. R. Besch
通讯作者：
H. R. Besch