The 1.85 Ã… resolution crystal structures of tissue factor in complex with humanized Fab D3h44 and of free humanized Fab D3h44:: Revisiting the solvation of antigen combining sites
The 1.85 Ã… resolution crystal structures of tissue factor in complex with humanized Fab D3h44 and of free humanized Fab D3h44:: Revisiting the solvation of antigen combining sites
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DOI：
10.1006/jmbi.2001.5036
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发表时间：
2001-10-12
影响因子：
5.6
通讯作者：
Muller, YA
中科院分区：
文献类型：
--
作者：
Faelber, K;Kirchhofer, D;Muller, YA
与有限的抗体-抗原对抗原蛋白的高分辨率结构数据形成鲜明对比的是，抗-抗体识别过程对高等生物的生存和防御策略的突出重要性。结构数据的限制是最严重的，不仅限于抗原-抗体复合物，而且延伸到未络合的抗原和抗体。我们报道了组织因子（TF）与人源化Fab片段D3h44复合物在1.85埃分辨率下的晶体结构，以及未配合的D3h44在相同分辨率下的结构。结合先前报道的未复杂TF的1.7埃晶体结构，产生了一个独特的机会来探索识别过程的细节。TF。D3h44界面具有大量的极性相互作用，包括多达46个溶剂分子。复杂构象的变化非常小，几乎完全局限于侧链的重新定向。结合表位与早期的诱变实验完全一致。对其他两种类似分辨率的抗体-抗原对的重新评估表明，所有这些复合物在界面的溶剂化、未络合和络合蛋白质中保留的溶剂位置的数量以及在络合形成时从表面排出并被结合伙伴的亲水原子取代的水分子的数量方面都非常相似。提出了如何利用这种高分辨率结构数据来指导人源化抗体亲和成熟的策略。(C) 2001学术出版社。
The outstanding importance of the anti-en-antibody recognition process for the survival and defence strategy of higher organisms is in sharp contrast to the limited high resolution structural data available on antibody-antigen pairs with antigenic proteins. The limitation is the most severe for structural data not restricted to the antigen-antibody complex but extending to the uncomplexed antigen and antibody. We report the crystal structure of the complex between tissue factor (TF) and the humanized Fab fragment D3h44 at a resolution of 1.85 Angstrom together with the, structure of uncomplexed D3h44 at the same resolution. In conjunction, with the previously reported 1.7 Angstrom crystal structure of uncomplexed TF, a unique opportunity is generated to explore details of the recognition process. The TF . D3h44 interface is characterised by a high number of polar interactions, including as may as 46 solvent molecules. Conformational changes upon complex formation are very small and almost exclusively limited to the reorientation of side-chains. The binding epitope is in complete agreement with earlier mutagenesis experiments. A revaluation of two other antibody-antigen pairs reported at similar resolutions, shows that all these complexes are very similar with respect to the solvation of the interface, the number of solvent positions conserved in the uncomplexed and complexed proteins and the number of water molecules expelled from the surface and replaced by hydrophilic atoms from the binding partner upon complex formation. A strategy is proposed on how to exploit this high resolution structural data to guide the affinity maturation of humanised antibodies. (C) 2001 Academic Press.