3MUG

Crystal structure of human Fab PG16, a broadly reactive and potent HIV-1 neutralizing antibody

3MUG の概要

• エントリーDOI: 10.2210/pdb3mug/pdb
• 関連するPDBエントリー: 3MUH
• 分子名称: Antibody PG16 Light Chain, Antibody PG16 Heavy Chain, 2-acetamido-2-deoxy-beta-D-glucopyranose-(1-4)-2-acetamido-2-deoxy-beta-D-glucopyranose, ... (5 entities in total)
• 機能のキーワード: pg16, fab, sulfotyrosine, hiv, immune system
• 由来する生物種: Homo sapiens (human); 詳細
• タンパク質・核酸の鎖数: 12
• 化学式量合計: 294886.45

構造登録者

Pejchal, R.,Walker, L.M.,Burton, D.R.,Wilson, I.A. (登録日: 2010-05-03, 公開日: 2010-06-16, 最終更新日: 2024-11-06)

主引用文献

Pejchal, R.,Walker, L.M.,Stanfield, R.L.,Phogat, S.K.,Koff, W.C.,Poignard, P.,Burton, D.R.,Wilson, I.A.
Structure and function of broadly reactive antibody PG16 reveal an H3 subdomain that mediates potent neutralization of HIV-1.
Proc.Natl.Acad.Sci.USA, 107:11483-11488, 2010

PubMed Abstract: Development of an effective vaccine against HIV-1 will likely require elicitation of broad and potent neutralizing antibodies against the trimeric surface envelope glycoprotein (Env). Monoclonal antibodies (mAbs) PG9 and PG16 neutralize approximately 80% of HIV-1 isolates across all clades with extraordinary potency and target novel epitopes preferentially expressed on Env trimers. As these neutralization properties are ideal for a vaccine-elicited antibody response to HIV-1, their structural basis was investigated. The crystal structure of the antigen-binding fragment (Fab) of PG16 at 2.5 A resolution revealed its unusually long, 28-residue, complementarity determining region (CDR) H3 forms a unique, stable subdomain that towers above the antibody surface. A 7-residue "specificity loop" on the "hammerhead" subdomain was identified that, when transplanted from PG16 to PG9 and vice versa, accounted for differences in the fine specificity and neutralization of these two mAbs. The PG16 electron density maps also revealed that a CDR H3 tyrosine was sulfated, which was confirmed for both PG9 (doubly) and PG16 (singly) by mass spectral analysis. We further showed that tyrosine sulfation plays a role in binding and neutralization. An N-linked glycan modification is observed in the variable light chain, but not required for antigen recognition. Further, the crystal structure of the PG9 light chain at 3.0 A facilitated homology modeling to support the presence of these unusual features in PG9. Thus, PG9 and PG16 use unique structural features to mediate potent neutralization of HIV-1 that may be of utility in antibody engineering and for high-affinity recognition of a variety of therapeutic targets.

PubMed: 20534513
DOI: 10.1073/pnas.1004600107

実験手法

X-RAY DIFFRACTION (2.49 Å)