ジャーナル: PLoS Pathog / 年: 2013 タイトル: Structure of a bimodular botulinum neurotoxin complex provides insights into its oral toxicity. 著者: Kwangkook Lee / Shenyan Gu / Lei Jin / Thi Tuc Nghi Le / Luisa W Cheng / Jasmin Strotmeier / Anna Magdalena Kruel / Guorui Yao / Kay Perry / Andreas Rummel / Rongsheng Jin / 要旨: Botulinum neurotoxins (BoNTs) are produced by Clostridium botulinum and cause the fatal disease botulism, a flaccid paralysis of the muscle. BoNTs are released together with several auxiliary ...Botulinum neurotoxins (BoNTs) are produced by Clostridium botulinum and cause the fatal disease botulism, a flaccid paralysis of the muscle. BoNTs are released together with several auxiliary proteins as progenitor toxin complexes (PTCs) to become highly potent oral poisons. Here, we report the structure of a ∼760 kDa 14-subunit large PTC of serotype A (L-PTC/A) and reveal insight into its absorption mechanism. Using a combination of X-ray crystallography, electron microscopy, and functional studies, we found that L-PTC/A consists of two structurally and functionally independent sub-complexes. A hetero-dimeric 290 kDa complex protects BoNT, while a hetero-dodecameric 470 kDa complex facilitates its absorption in the harsh environment of the gastrointestinal tract. BoNT absorption is mediated by nine glycan-binding sites on the dodecameric sub-complex that forms multivalent interactions with carbohydrate receptors on intestinal epithelial cells. We identified monosaccharides that blocked oral BoNT intoxication in mice, which suggests a new strategy for the development of preventive countermeasures for BoNTs based on carbohydrate receptor mimicry.
FULL-LENGTH HA70 WAS CLEAVED INTO CHAIN A (UNP RESIDUES 2-189) AND CHAIN B (UNP RESIDUES 206-626). ...FULL-LENGTH HA70 WAS CLEAVED INTO CHAIN A (UNP RESIDUES 2-189) AND CHAIN B (UNP RESIDUES 206-626). THE EXACT CLEAVAGE POINT ON THE TKNIPTNNIFNSKVSS LINKING SEQUENCE IS NOT KNOWN.
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実験情報
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実験
実験
手法: X線回折 / 使用した結晶の数: 1
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試料調製
結晶
マシュー密度: 5.26 Å3/Da / 溶媒含有率: 76.6 %
結晶化
温度: 292 K / 手法: 蒸発脱水法 / pH: 4.4 詳細: 0.1 M sodium acetate, 1.5 M ammonium chloride, pH 4.4, EVAPORATION, temperature 292.0K