ジャーナル: Proc Natl Acad Sci U S A / 年: 2015 タイトル: Cryo-EM structures elucidate neutralizing mechanisms of anti-chikungunya human monoclonal antibodies with therapeutic activity. 著者: Feng Long / Rachel H Fong / Stephen K Austin / Zhenguo Chen / Thomas Klose / Andrei Fokine / Yue Liu / Jason Porta / Gopal Sapparapu / Wataru Akahata / Benjamin J Doranz / James E Crowe / ...著者: Feng Long / Rachel H Fong / Stephen K Austin / Zhenguo Chen / Thomas Klose / Andrei Fokine / Yue Liu / Jason Porta / Gopal Sapparapu / Wataru Akahata / Benjamin J Doranz / James E Crowe / Michael S Diamond / Michael G Rossmann / 要旨: Chikungunya virus (CHIKV) is a mosquito-transmitted alphavirus that causes severe acute and chronic disease in humans. Although highly inhibitory murine and human monoclonal antibodies (mAbs) have ...Chikungunya virus (CHIKV) is a mosquito-transmitted alphavirus that causes severe acute and chronic disease in humans. Although highly inhibitory murine and human monoclonal antibodies (mAbs) have been generated, the structural basis of their neutralizing activity remains poorly characterized. Here, we determined the cryo-EM structures of chikungunya virus-like particles complexed with antibody fragments (Fab) of two highly protective human mAbs, 4J21 and 5M16, that block virus fusion with host membranes. Both mAbs bind primarily to sites within the A and B domains, as well as to the B domain's β-ribbon connector of the viral glycoprotein E2. The footprints of these antibodies on the viral surface were consistent with results from loss-of-binding studies using an alanine scanning mutagenesis-based epitope mapping approach. The Fab fragments stabilized the position of the B domain relative to the virus, particularly for the complex with 5M16. This finding is consistent with a mechanism of neutralization in which anti-CHIKV mAbs that bridge the A and B domains impede movement of the B domain away from the underlying fusion loop on the E1 glycoprotein and therefore block the requisite pH-dependent fusion of viral and host membranes.
ダウンロード / ファイル: emd_3148.map.gz / 形式: CCP4 / 大きさ: 300.3 MB / タイプ: IMAGE STORED AS FLOATING POINT NUMBER (4 BYTES)
注釈
Reconstruction of CHIKV VLP in complex with Fab molecules
ボクセルのサイズ
X=Y=Z: 2.39 Å
密度
表面レベル
登録者による: 1.5 / ムービー #1: 1.5
最小 - 最大
-15.54661655 - 15.48305511
平均 (標準偏差)
0.09012548 (±1.98130405)
対称性
空間群: 1
詳細
EMDB XML:
マップ形状
Axis order
X
Y
Z
Origin
-216
-216
-216
サイズ
432
432
432
Spacing
432
432
432
セル
A=B=C: 1032.4801 Å α=β=γ: 90.0 °
CCP4マップ ヘッダ情報:
mode
Image stored as Reals
Å/pix. X/Y/Z
2.39
2.39
2.39
M x/y/z
432
432
432
origin x/y/z
0.000
0.000
0.000
length x/y/z
1032.480
1032.480
1032.480
α/β/γ
90.000
90.000
90.000
MAP C/R/S
1
2
3
start NC/NR/NS
-216
-216
-216
NC/NR/NS
432
432
432
D min/max/mean
-15.547
15.483
0.090
-
添付データ
-
試料の構成要素
-
全体 : Electron Cryo-microscopy of Chikungunya VLP in complex with human...
全体
名称: Electron Cryo-microscopy of Chikungunya VLP in complex with human neutralizing antibody Fab 4J21
要素
試料: Electron Cryo-microscopy of Chikungunya VLP in complex with human neutralizing antibody Fab 4J21
ウイルス: Chikungunya virus (チクングニヤウイルス)
タンパク質・ペプチド: Fab 4J21
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超分子 #1000: Electron Cryo-microscopy of Chikungunya VLP in complex with human...
超分子
名称: Electron Cryo-microscopy of Chikungunya VLP in complex with human neutralizing antibody Fab 4J21 タイプ: sample / ID: 1000 集合状態: one Fab binds to one envelope protein on the surface of virus Number unique components: 2