3-DIMENSIONAL STRUCTURE OF AN ANTIBODY-ANTIGEN COMPLEX
3-DIMENSIONAL STRUCTURE OF AN ANTIBODY-ANTIGEN COMPLEX
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DOI：
10.1073/pnas.84.22.8075
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发表时间：
1987-11-01
影响因子：
11.1
通讯作者：
DAVIES, DR
中科院分区：
文献类型：
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作者：
SHERIFF, S;SILVERTON, EW;DAVIES, DR
我们已经确定了两种晶体形式的抗溶菌酶Fab-溶菌酶复合物的三维结构的X-射线晶体学。溶菌酶上的表位由三个顺序分离的亚位点组成，包括一个长的、几乎连续的位点，从Gln-41到Tyr-53，以及一个从Gly-67到Pro-70。与溶菌酶相互作用的抗体残基出现在六个互补决定区中的每一个中，并且还包括一个框架残基。Arg-45和Arg-68在溶菌酶的表面上形成脊，其结合在抗体表面上的凹槽中。否则，两种蛋白质之间的相互作用表面相对平坦，尽管它在边缘卷曲。相互作用的表面约为26 × 104。19. ANG..在界面处没有发现水分子。两个丝氨酸上的正电荷由来自抗体重链的Glu-35和Glu-50的负电荷补充。抗原溶菌酶的骨架结构大部分未受干扰，尽管表位区域有一些变化，最明显的是Pro-70。不在表位中的一条侧链Trp-63经历约90 °的旋转。180.degree.关于C βsbd.C.gamma.邦德两种晶型中的Fab肘形弯曲相差7 °。
We have determined the three-dimensional structure of two crystal forms of an antilysozyme Fab-lysozyme complex by x-ray crystallography. The epitope on lysozyme consists of three sequentially separated subsites, including one long, nearly continuous, site from Gln-41 through Tyr-53 and one from Gly-67 through Pro-70. Antibody residues interacting with lysozyme occur in each of the six complementarity-determining regions and also include one framework residue. Arg-45 and Arg-68 form a ridge on the surface of lysozyme, which binds in a groove on the antibody surface. Otherwise the surface of interaction between the two proteins is relatively flat, although it curls at the edges. The surface of interaction is approximately 26 .times. 19 .ANG.. No water molecules are found in the interface. The positive charge on the two arginines is complemented by the negative charge of Glu-35 and Glu-50 from the heavy chain of the antibody. The backbone structure of the antigen, lysozyme, is mostly unperturbed, although there are some changes in the epitope region, most notably Pro-70. One side chain not in the epitope, Trp-63, undergoes a rotation of .apprxeq. 180.degree. about the C.beta..sbd.C.gamma. bond. The Fab elbow bends in the two crystal forms differ by 7.degree.