2I27

Crystal Structure Analysis of the Nurse Shark New Antigen Receptor Ancestral variable domain

2I27 の概要

• エントリーDOI: 10.2210/pdb2i27/pdb
• 関連するPDBエントリー: 2I24 2I25 2I26
• 分子名称: New Antigen Receptor Ancestral (2 entities in total)
• 機能のキーワード: immunoglobulin fold, immune system
• 由来する生物種: Ginglymostoma cirratum (nurse shark)
• タンパク質・核酸の鎖数: 2
• 化学式量合計: 26588.91

構造登録者

Stanfield, R.L.,Wilson, I.A. (登録日: 2006-08-15, 公開日: 2007-03-06, 最終更新日: 2024-11-13)

主引用文献

Stanfield, R.L.,Dooley, H.,Verdino, P.,Flajnik, M.F.,Wilson, I.A.
Maturation of Shark Single-domain (IgNAR) Antibodies: Evidence for Induced-fit Binding.
J.Mol.Biol., 367:358-372, 2007

PubMed Abstract: Sharks express an unusual heavy-chain isotype called IgNAR, whose variable regions bind antigen as independent soluble domains. To further probe affinity maturation of the IgNAR response, we structurally characterized the germline and somatically matured versions of a type II variable (V) region, both in the presence and absence of its antigen, hen egg-white lysozyme. Despite a disulfide bond linking complementarity determining regions (CDRs) 1 and 3, both germline and somatically matured V regions displayed significant structural changes in these CDRs upon complex formation with antigen. Somatic mutations in the IgNAR V region serve to increase the number of contacts with antigen, as reflected by a tenfold increase in affinity, and one of these mutations appears to stabilize the CDR3 region. In addition, a residue in the HV4 loop plays an important role in antibody-antigen interaction, consistent with the high rate of somatic mutations in this non-CDR loop.

PubMed: 17258766
DOI: 10.1016/j.jmb.2006.12.045

実験手法

X-RAY DIFFRACTION (1.92 Å)