ANALYSIS OF MEMBRANE AND SURFACE PROTEIN SEQUENCES WITH THE HYDROPHOBIC MOMENT PLOT
ANALYSIS OF MEMBRANE AND SURFACE PROTEIN SEQUENCES WITH THE HYDROPHOBIC MOMENT PLOT
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DOI：
10.1016/0022-2836(84)90309-7
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发表时间：
1984-01-01
影响因子：
5.6
通讯作者：
WALL, R
中科院分区：
文献类型：
--
作者：
EISENBERG, D;SCHWARZ, E;WALL, R
开发了一种算法，其识别α-参与膜蛋白与脂双层相互作用的螺旋，并将其与可溶性蛋白中的螺旋区分开来。然后借助疏水矩图对膜相关螺旋进行分类，在该图上绘制了每个螺旋的疏水矩作为其疏水性的函数。疏水矩的大小测量螺旋的两亲性（因此其倾向于在疏水和亲水相之间寻找表面），疏水性测量其对膜内部的亲和力。α-膜蛋白的片段螺旋倾向于落在疏水矩图的3个区域中的1个：单体跨膜锚（I类HLA跨膜序列）位于最高疏水性和最小疏水矩的区域;假定成对的螺旋（如表面免疫球蛋白的跨膜M片段）和在膜中捆绑在一起的螺旋来自表面寻求蛋白（如蜂毒肽）的螺旋落在具有更高疏水性矩和更小疏水性的相邻区域;而来自表面寻求蛋白（如蜂毒肽）的螺旋落在具有更高疏水性矩的区域。α-球状蛋白的螺旋主要位于平均疏水性和疏水矩较低的区域。应用这些方法对白喉毒素的序列表明，在片段B中有4个跨膜螺旋和一个表面寻找螺旋，该片段已知具有跨膜功能。
An algorithm was developed which identifies .alpha.-helices involved in the interactions of membrane proteins with lipid bilayers and which distinguishes them from helices in soluble proteins. The membrane-associated helices are then classified with the aid of the hydrophobic moment plot, on which the hydrophobic moment of each helix is plotted as a function of its hydrophobicity. The magnitude of hydrophobic moment measures the amphiphilicity of the helix (and hence its tendency to seek a surface between hydrophobic and hydrophilic phases), and the hydrophobicity measures its affinity for the membrane interior. Segments of membrane proteins in .alpha.-helices tend to fall in 1 of 3 regions of a hydrophobic moment plot: monomeric transmembrane anchors (class I HLA transmembrane sequences) lie in the region of highest hydrophobicity and smallest hydrophobic moment; helices presumed to be paired (such as the transmembrane M segments of surface immunoglobulins) and helices which are bundled together in membranes (such as bacteriorhodopsin) fall in the adjacent region with higher hydrophobic moment and smaller hydrophobicity; and helices from surface-seeking proteins (such as melittin) fall in the region with still higher hydrophobic moment. .alpha.-Helices from globular proteins mainly fall in a region of lower mean hydrophobicity and hydrophobic moment. Application of these methods to the sequence of diphtheria toxin suggests 4 transmembrane helices and a surface-seeking helix in fragment B, the moiety known to have transmembrane function.