CANONICAL STRUCTURES FOR THE HYPERVARIABLE REGIONS OF IMMUNOGLOBULINS
CANONICAL STRUCTURES FOR THE HYPERVARIABLE REGIONS OF IMMUNOGLOBULINS
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DOI：
10.1016/0022-2836(87)90412-8
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发表时间：
1987-08-20
影响因子：
5.6
通讯作者：
LESK, AM
中科院分区：
文献类型：
--
作者：
CHOTHIA, C;LESK, AM
我们分析了免疫球蛋白Fab和VL片段的原子结构，以确定它们的氨基酸序列与其抗原结合部位的三维结构之间的关系。我们确定了相对较少的残基，通过它们的包装、氢键或承担不寻常的vphi、psi的能力。或者欧米茄。构象，主要负责高变区的主链构象。这些残基被发现出现在高变区和保守的β-折叠框架内的位置。对未知结构的免疫球蛋白序列的研究表明，许多免疫球蛋白具有与已知结构之一大小相似的高变区，并在负责观察到的构象的位点含有相同的残基。这意味着这些高变区的构象与已知结构中的构象接近。对于五个高变区，构象谱似乎仅限于相对较少的离散结构类。我们把常见的高变区的主链构象称为“正则结构”。在实验确定免疫球蛋白结构之前，通过预测免疫球蛋白结构来检验和改进分析的准确性。
We have analysed the atomic structures of Fab and VL fragments of immunoglobulins to determine the relationship between their amino acid sequences and the three-dimensional structures of their antigen binding sites. We identify the relatively few residues that, through their packing, hydrogen bonding or the ability to assume unusual .vphi., .psi. or .omega. conformations, are primarily responsible for the main-chain of conformations of the hypervariable regions. These residues are found to occur at sites within the hypervariable regions and in the conserved .beta.-sheet framework. Examination of the sequences of immunoglobulins of unknown structures shows that many have hypervariable regions that are similar in size to one of the known structures and contain identical residues at the sites responsible for the observed conformation. This implies that these hypervariable regions have conformations close to those in the known structures. For five of the hypervariable regions, the repertoire of conformations appears to be limited to a relatively small number of discrete structural classes. We call the commonly occurring main-chain conformations of the hypervariable regions "canonical structures". The accuracy of the analysis is being tested and refined by the prediction of immunoglobulin structures prior to their experimental determination.