ボツリヌム神経毒素A複合体によるE-カデリンの粘着の破壊の分子基礎
Kwangkook Lee1, Xiaofen Zhong2, Shenyan Gu1
1Department of Physiology and Biophysics, University of California, Irvine, CA 92697, USA.
まとめ
ボトリヌム神経毒素 (BoNT/A) は,E-カデリンと炭水化物を結合するヘマグルチニン (HA) を使用して腸壁を横切ります. この相互作用は細胞の結合を損なうため,毒素の吸収と経口毒性を可能にします.
科学分野:
- 分子生物学は分子生物学である.
- 構造生物学 構造生物学とは
- 微生物学 微生物学とは
背景:
- ボトリヌス神経毒素 (BoNT) の腸内障壁を横断するメカニズムは不明である.
- BoNTは,クロストリジウムボツリン菌によって生成される強力な神経毒素です.
研究 の 目的:
- BoNT/Aのヘマグルチニン (HA) が腸内吸収を促進する分子メカニズムを解明する.
- 宿主細胞とのHA相互作用の構造的基礎を決定する.
主な方法:
- E-カデリンに結合したBoNT/A HA複合体の構造を決定するX線結晶学.
- 完全なBoNT/A複合体の再結合生産.
- マウスモデルでのin vivo経口毒性アッセイ.
主要な成果:
- 結晶構造は,HA複合体のE-カデリンと細胞表面の炭水化物との特定の結合を明らかにした.
- HAがE-カデリンに結合すると,単体状態に閉じ込められ,細胞間結合が破壊されます.
- HAのE-カデリンまたは炭水化物の結合を妨害することで,BoNT/Aの経口毒性がin vivoで著しく低下しました.
結論:
- BoNT/A HA複合体は,二重結合 (E-カデリンと炭水化物) を使用して,腸内皮質障壁を突破します.
- この分子メカニズムは,HAsがBoNT/Aの経口毒性にどのように貢献するか説明し,治療的介入のターゲットを提供します.
関連する概念動画
Structure of Cadherins
3.9K
The cadherins were one of the first cell adhesion molecules discovered; the term “cadherins” is based on their calcium-dependent adhering properties. The first cadherins discovered on the epithelial, neuronal, and placental cells were named E-cadherin, P-cadherin, and N-cadherin, respectively. These classical cadherins share sequence and structural similarities. Other cadherins, including those involved in cell signaling, are grouped into non-classical cadherins. This...
3.9K
Bacterial Toxins
132
Bacterial toxins are sophisticated virulence factors that enable pathogenic bacteria to interact with, invade, and damage host tissues. These toxins fall broadly into two types: protein exotoxins, which are secreted into the environment and target specific host receptors, and lipopolysaccharide endotoxins, which are structural components of the bacterial outer membrane released primarily during bacterial lysis or membrane shedding. Exotoxins generally act more selectively, binding to cell...
132
Fusion of Secretory Vesicles with the Plasma Membrane
15.9K
Proteins and neurotransmitters in secretory vesicles can be released from a cell upon vesicle docking, priming, and fusion with the plasma membrane. Vesicles are docked and primed in preparation for the quick exocytosis of their contents in response to a stimulus. The fusion process is mainly carried out by a SNAP Receptor or SNARE complex, consisting of synaptobrevin, syntaxin-1, and SNAP-25.
In 1993, Jim Rothman proposed that the antiparallel pairing of vesicular and transmembrane SNAREs, or...
In 1993, Jim Rothman proposed that the antiparallel pairing of vesicular and transmembrane SNAREs, or...
15.9K
Cadherins in Tissue Organization
3.5K
The cadherins are a superfamily of cell adhesion molecules comprising over 180 variants, with specific tissues expressing a particular combination of cadherin types. Cadherins generally exhibit homophilic binding; i.e., cadherins on one cell bind to cadherins of the same or closely related type on another cell. Thus, cells of the same type have a specific affinity to bind to each other and sort themselves into clusters to form tissues.
Cell Sorting During Development
Cell sorting plays an...
Cell Sorting During Development
Cell sorting plays an...
3.5K
Adherens Junctions
5.8K
Strong contact points between adjacent cells anchor them to each other, forming tissues. Such anchoring junctions are of two types – adherens junctions and desmosomes. Adherens junctions are abundant in tissues such as epithelium and endothelium, forming a continuous zone of adhesion called the adhesion belt. In other tissues, such as heart muscle, they appear as clusters, linking the cells to produce coordinated heart muscle contraction.
Adherens Junctions are Dynamic
Adherens Junctions are Dynamic
5.8K
Directly Acting Muscle Relaxants: Dantrolene and Botulinum Toxin
2.2K
Directly acting muscle relaxants like dantrolene and botulinum toxin (BoNT) have distinct mechanisms and applications. Dantrolene, a hydantoin derivative, acts on the ryanodine receptor (RYR1) in skeletal muscle cells. RYR1 are calcium channels present at the sarcoplasmic reticulum membrane. In response to excitation, they release calcium ions from the sarcoplasmic reticulum to the cytosol. Calcium promotes actin-myosin-mediated contraction of muscles.
The binding of dantrolene to the RYR1...
The binding of dantrolene to the RYR1...
2.2K


