National Institutes of Health/National Institute of General Medical Sciences (NIH/NIGMS)
R35 GM131835
米国
引用
ジャーナル: Blood / 年: 2023 タイトル: Cryo-EM structures of human arachidonate 12S-lipoxygenase bound to endogenous and exogenous inhibitors. 著者: Jesse I Mobbs / Katrina A Black / Michelle Tran / Wessel A C Burger / Hariprasad Venugopal / Theodore R Holman / Michael Holinstat / David M Thal / Alisa Glukhova / 要旨: Human 12-lipoxygenase (12-LOX) is a key enzyme involved in platelet activation, and the regulation of its activity has been targeted for the treatment of heparin-induced thrombocytopenia. Despite the ...Human 12-lipoxygenase (12-LOX) is a key enzyme involved in platelet activation, and the regulation of its activity has been targeted for the treatment of heparin-induced thrombocytopenia. Despite the clinical importance of 12-LOX, the exact mechanisms by which it affects platelet activation are not fully understood, and the lack of structural information has limited drug discovery efforts. In this study, we used single-particle cryo-electron microscopy to determine high-resolution structures (1.7-2.8 Å) of human 12-LOX. Our results showed that 12-LOX can exist in multiple oligomeric states, from monomer to hexamer, which may affect its catalytic activity and membrane association. We also identified different conformations within the 12-LOX dimer, which likely represent different time points in its catalytic cycle. Furthermore, we identified small molecules bound to 12-LOX. The active site of the 12-LOX tetramer was occupied by an endogenous 12-LOX inhibitor, a long-chain acyl coenzyme A. In addition, we found that the 12-LOX hexamer can simultaneously bind to arachidonic acid and ML355, a selective 12-LOX inhibitor that has passed a phase 1 clinical trial for the treatment of heparin-induced thrombocytopenia and received a fast-track designation by the Food and Drug Administration. Overall, our findings provide novel insights into the assembly of 12-LOX oligomers, their catalytic mechanism, and small molecule binding, paving the way for further drug development targeting the 12-LOX enzyme.
モード: BRIGHT FIELD / 倍率(補正後): 105000 X / 最大 デフォーカス(公称値): 1500 nm / 最小 デフォーカス(公称値): 500 nm / Cs: 2.7 mm / C2レンズ絞り径: 50 µm
撮影
電子線照射量: 60 e/Å2 / フィルム・検出器のモデル: GATAN K3 (6k x 4k)
-
解析
ソフトウェア
名称: PHENIX / バージョン: 1.20.1_4487: / 分類: 精密化
EMソフトウェア
ID
名称
バージョン
カテゴリ
4
Gctf
1.18
CTF補正
7
UCSF Chimera
モデルフィッティング
12
cryoSPARC
3次元再構成
19
PHENIX
モデル精密化
CTF補正
タイプ: PHASE FLIPPING AND AMPLITUDE CORRECTION
粒子像の選択
選択した粒子像数: 2736609
3次元再構成
解像度: 2.3 Å / 解像度の算出法: OTHER / 粒子像の数: 126914 詳細: This is a composite map. The resolution (FSC 0.143) for the "open" subunit is 2.33, and for the "closed" subunit is 2.54 対称性のタイプ: POINT