Three-dimensional structure of two crystal forms of FabR19.9 from a monoclonal anti-arsonate antibody.
Three-dimensional structure of two crystal forms of FabR19.9 from a monoclonal anti-arsonate antibody.
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来自单克隆抗胂酸盐抗体的 FabR19.9 两种晶型的三维结构。
DOI：
10.1073/pnas.89.20.9429
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发表时间：
1992
影响因子：
11.1
通讯作者：
Nisonoff,A
中科院分区：
文献类型：
--
作者：
Lascombe,MB;Alzari,PM;Poljak,RJ;Nisonoff,A
已通过X射线衍射技术以两种结晶形式（I和II）分别测定了来自充分表征的抗对偶氮苯胂酸单克隆抗体的FabR19.9的三维结构，分辨率分别为2.8和2.7 A。在两种形式中观察到Fab的基本上相同的三级和四级结构。主要的区别在于分子间的接触，这被解释为有利于从亚稳态形式I到更稳定的形式II的不可逆转变。重链的第三个互补决定区（H3）在结合位点上向后折叠，需要重排才能结合半抗原。对H3的这种动态要求与其在结构中的移动性一致，并且可以解释半抗原结合到否则不可接近的抗体结合位点。
The three-dimensional structure of FabR19.9 from a well-characterized anti-p-azobenzenearsonate monoclonal antibody has been determined by x-ray diffraction techniques in two crystalline forms (I and II) to a resolution of 2.8 and 2.7 A, respectively. Essentially the same tertiary and quaternary structure of the Fab is observed in the two forms. The major difference resides in the intermolecular contacts, which are interpreted to favor an irreversible transition from the metastable form I to the more stable form II. The third complementarity-determining region of the heavy chain (H3) folds back over the combining site and requires rearrangement for hapten binding. This dynamic requirement on H3 is consistent with its mobility in the structure and can explain hapten binding to an otherwise inaccessible antibody combining site.