4NQS

Knob-into-hole IgG Fc

4NQS の概要

• エントリーDOI: 10.2210/pdb4nqs/pdb
• 関連するPDBエントリー: 4NQT 4NQU
• 分子名称: Ig gamma-1 chain C region, miniZ, ... (4 entities in total)
• 機能のキーワード: immunoglobulin, immune system
• 由来する生物種: Homo sapiens (human); 詳細
• 細胞内の位置: Secreted: P01857 P01857
• タンパク質・核酸の鎖数: 8
• 化学式量合計: 113173.82

構造登録者

Eigenbrot, C.,Ultsch, M. (登録日: 2013-11-25, 公開日: 2014-03-12, 最終更新日: 2024-11-06)

主引用文献

Elliott, J.M.,Ultsch, M.,Lee, J.,Tong, R.,Takeda, K.,Spiess, C.,Eigenbrot, C.,Scheer, J.M.
Antiparallel Conformation of Knob and Hole Aglycosylated Half-Antibody Homodimers Is Mediated by a CH2-CH3 Hydrophobic Interaction.
J.Mol.Biol., 426:1947-1957, 2014

PubMed Abstract: Bispecific antibody and antibody-like molecules are of wide interest as potential therapeutics that can recognize two distinct targets. Among the variety of ways such molecules have been engineered is by creating "knob" and "hole" heterodimerization sites in the CH3 domains of two antibody heavy chains. The molecules produced in this manner maintain their biological activities while differing very little from the native human IgG sequence. To better understand the knob-into-hole interface, the molecular mechanism of heterodimerization, and to engineer Fc domains that could improve the assembly and purity of heterodimeric reaction products, we sought crystal structures of aglycosylated heterodimeric and homodimeric "knob" and "hole" Fc fragments derived from bacterial expression. The structure of the knob-into-hole Fc was determined at 2.64 Å. Except for the sites of mutation, the structure is very similar to that of the native human IgG1 Fc, consistent with a heterodimer interaction kinetic K(D) of <1 nM. Homodimers of the "knob" and "hole" mutants were also obtained, and their X-ray structures were determined at resolutions 2.5 Å and 2.1 Å, respectively. Both kinds of homodimers adopt a head-to-tail quaternary structure and thus do not contain direct knob/knob or hole/hole CH3 interactions. The head-to-tail arrangement was disfavored by adding site-directed mutations at F241 and F243 in the CH2 domains, leading to increases in both rate and efficiency of bispecific (heterodimer) assembly.

PubMed: 24576605
DOI: 10.1016/j.jmb.2014.02.015

実験手法

X-RAY DIFFRACTION (2.64 Å)