A SIMPLE METHOD FOR DISPLAYING THE HYDROPATHIC CHARACTER OF A PROTEIN
A SIMPLE METHOD FOR DISPLAYING THE HYDROPATHIC CHARACTER OF A PROTEIN
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DOI：
10.1016/0022-2836(82)90515-0
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发表时间：
1982-01-01
影响因子：
5.6
通讯作者：
DOOLITTLE, RF
中科院分区：
文献类型：
--
作者：
KYTE, J;DOOLITTLE, RF
设计了一个计算机程序，可以沿着氨基酸序列逐步评估蛋白质的亲水性和疏水性。为此目的，组成了一个亲水量表，其中考虑了20个氨基酸侧链中的每个氨基酸的亲疏水性。该量表是基于从文献中得出的实验观察的综合。该程序使用移动段方法，随着序列的推进，连续确定预定长度段内的平均亲水性。从氨基端到羧基端绘制连续的分数。与此同时，一条中点线被打印出来，这条中点线对应于大多数测序蛋白质中发现的氨基酸组成的亲水性的大平均值。在可溶性的球状蛋白质中，它们序列的内部部分与中点线疏水侧出现的区域以及外部部分与亲水性侧出现的区域之间存在显著的对应关系。通过比较绘制的值和晶体学确定的已知结构，证明了这种相关性。在膜结合蛋白的情况下，它们位于脂质双分子层内的部分序列也被中点线疏水侧的大片不间断区域清楚地描绘出来。因此，这些蛋白质的跨膜片段可以通过这种方法来识别。虽然这种方法并不独特，而且体现了长期以来受到赞赏的原理，但它的简单性和图形性使其成为评估蛋白质结构的非常有用的工具。
A computer program that progressively evaluates the hydrophilicity and hydrophobicity of a protein along its amino acid sequence was devised. For this purpose, a hydropathy scale was composed wherein the hydrophilic and hydrophobic properties of each of the 20 amino acid side-chains is taken into consideration. The scale is based on an amalgam of experimental observations derived from the literature. The program uses a moving-segment approach that continuously determines the average hydropathy within a segment of predetermined length as it advances through the sequence. The consecutive scores are plotted from the amino to the carboxy terminus. At the same time, a midpoint line is printed that corresponds to the grand average of the hydropathy of the amino acid compositions found in most of the sequenced proteins. In the case of soluble, globular proteins, there is a remarkable correspondence between the interior portions of their sequence and the regions appearing on the hydrophobic side of the midpoint line as well as the exterior portions and the regions on the hydrophilic side. The correlation was demonstrated by comparisons between the plotted values and known structures determined by crystallography. In the case of membrane-bound proteins, the portions of their sequences that are located within the lipid bilayer are also clearly delineated by large uninterrupted areas on the hydrophobic side of the midpoint line. As such, the membrane-spanning segments of these proteins can be identified by this procedure. Although the method is not unique and embodies principles that have long been appreciated, its simplicity and its graphic nature make it a very useful tool for the evaluation of protein structures.