ジャーナル: Biochimie / 年: 2019 タイトル: 3D structure of the natural tetrameric form of human butyrylcholinesterase as revealed by cryoEM, SAXS and MD. 著者: Konstantin M Boyko / Timur N Baymukhametov / Yury M Chesnokov / Michael Hons / Sofya V Lushchekina / Petr V Konarev / Alexey V Lipkin / Alexandre L Vasiliev / Patrick Masson / Vladimir O ...著者: Konstantin M Boyko / Timur N Baymukhametov / Yury M Chesnokov / Michael Hons / Sofya V Lushchekina / Petr V Konarev / Alexey V Lipkin / Alexandre L Vasiliev / Patrick Masson / Vladimir O Popov / Michail V Kovalchuk / 要旨: Human plasma butyrylcholinesterase (BChE) is an endogenous bioscavenger that hydrolyzes numerous medicamentous and poisonous esters and scavenges potent organophosphorus nerve agents. BChE is thus a ...Human plasma butyrylcholinesterase (BChE) is an endogenous bioscavenger that hydrolyzes numerous medicamentous and poisonous esters and scavenges potent organophosphorus nerve agents. BChE is thus a marker for the diagnosis of OP poisoning. It is also considered a therapeutic target against Alzheimer's disease. Although the X-ray structure of a partially deglycosylated monomer of human BChE was solved 15 years ago, all attempts to determine the 3D structure of the natural full-length glycosylated tetrameric human BChE have been unsuccessful so far. Here, a combination of three complementary structural methods-single-particle cryo-electron microscopy, molecular dynamics and small-angle X-ray scattering-were implemented to elucidate the overall structural and spatial organization of the natural tetrameric human plasma BChE. A 7.6 Å cryoEM map clearly shows the major features of the enzyme: a dimer of dimers with a nonplanar monomer arrangement, in which the interconnecting super helix complex PRAD-(WAT)-peptide C-terminal tail is located in the center of the tetramer, nearly perpendicular to its plane, and is plunged deep between the four subunits. Molecular dynamics simulations allowed optimization of the geometry of the molecule and reconstruction of the structural features invisible in the cryoEM density, i.e., glycan chains and glycan interdimer contact areas, as well as intermonomer disulfide bridges at the C-terminal tail. Finally, SAXS data were used to confirm the consistency of the obtained model with the experimental data. The tetramer organization of BChE is unique in that the four subunits are joined at their C-termini through noncovalent contacts with a short polyproline-rich peptide. This tetramer structure could serve as a model for the design of highly stable glycosylated tetramers.
全体 : Natural tetrameric form of human butyrylcholinesterase
全体
名称: Natural tetrameric form of human butyrylcholinesterase
要素
複合体: Natural tetrameric form of human butyrylcholinesterase
タンパク質・ペプチド: Natural tetrameric form of human butyrylcholinesterase
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超分子 #1: Natural tetrameric form of human butyrylcholinesterase
超分子
名称: Natural tetrameric form of human butyrylcholinesterase タイプ: complex / ID: 1 / 親要素: 0 / 含まれる分子: all
由来(天然)
生物種: Homo sapiens (ヒト)
分子量
理論値: 335 KDa
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分子 #1: Natural tetrameric form of human butyrylcholinesterase
分子
名称: Natural tetrameric form of human butyrylcholinesterase タイプ: protein_or_peptide / ID: 1 詳細: Glycan chains are attached to the following residues: 17,57,106, 241, 256, 341, 455, 481, 486. 光学異性体: LEVO / EC番号: cholinesterase