Toxin B/TcdB 蛋白, C. difficile (His)

Toxin B/TcdB protein is the precursor of the cytotoxin TcdB, which can strategically destroy the colon epithelium and cause host inflammatory response and diarrhea in Clostridium difficile infection. Compared with TcdA, TcdB has higher virulence and is essential for eliciting host responses. Toxin B/TcdB Protein, C. difficile (His) is the recombinant Toxin B/TcdB protein, expressed by E. coli , with C-6*His labeled tag. The total length of Toxin B/TcdB Protein, C. difficile (His) is 543 a.a., with molecular weight of approximately 65 kDa.

毒素 B/TcdB 蛋白作为细胞毒素的前体，战略性地靶向并破坏结肠上皮，从而引发宿主炎症和先天免疫反应，表现为腹泻和伪膜性结肠炎。这种细胞毒素 TcdB 在艰难梭菌感染的病理学中发挥着核心作用，艰难梭菌感染是一种机会性病原体，当正常肠道微生物群被破坏时，就会在结肠中生存。与 TcdA 相比，TcdB 表现出更高的毒力，尤其有助于引发宿主炎症和先天免疫反应。作为毒素的前体，毒素 B 进入宿主细胞并进行自动加工，导致活性毒素葡萄糖基转移酶 TcdB 释放到宿主细胞质中。该毒素通过与 FZD1、FZD2 和 FZD7 等卷曲受体结合来靶向结肠上皮，通过网格蛋白介导的内吞作用进入宿主细胞。虽然卷曲受体主要存在于结肠上皮中，但也已鉴定出其他受体，如 CSPG4 或 NECTIN3/PVRL3。碳水化合物和硫酸化糖胺聚糖在宿主细胞表面的结合也有助于细胞进入。一旦进入宿主细胞，内体中的酸化就会触发易位区域的膜插入和孔形成，从而促进 GT44 和肽酶 C80 结构域穿过内体膜的易位。这通过自催化处理启动肽酶 C80 结构域的激活，释放 N 末端部分（葡萄糖基转移酶 TcdB）作为胞质溶胶中的活性毒素。该毒素的活性形式通过单糖基化作用，使宿主细胞中 Rho 家族（Rac1、RhoA、RhoB、RhoC、RhoG 和 Cdc42）的小 GTP 酶失活，阻止下游效应器识别，从而破坏肌动蛋白细胞骨架并诱导细胞死亡。这一系列事件导致结肠上皮屏障功能丧失，导致艰难梭菌感染的严重表现。

Measured by its ability to hydrolyze UDP-Glucose. The specific activity is 33.1357 pmol/min/μg, as measured under the described conditions.

Others

E. coli

C-6*His

P18177 (M1-L543)

4914074

MSLVNRKQLEKMANVRFRTQEDEYVAILDALEEYHNMSENTVVEKYLKLKDINSLTDIYIDTYKKSGRNKALKKFKEYLVTEVLELKNNNLTPVEKNLHFVWIGGQINDTAINYINQWKDVNSDYNVNVFYDSNAFLINTLKKTVVESAINDTLESFRENLNDPRFDYNKFFRKRMEIIYDKQKNFINYYKAQREENPELIIDDIVKTYLSNEYSKEIDELNTYIEESLNKITQNSGNDVRNFEEFKNGESFNLYEQELVERWNLAAASDILRISALKEIGGMYLDVDMLPGIQPDLFESIEKPSSVTVDFWEMTKLEAIMKYKEYIPEYTSEHFDMLDEEVQSSFESVLASKSDKSEIFSSLGDMEASPLEVKIAFNSKGIINQGLISVKDSYCSNLIVKQIENRYKILNNSLNPAISEDNDFNTTTNTFIDSIMAEANADNGRFMMELGKYLRVGFFPDVKTTINLSGPEAYAAAYQDLLMFKEGSMNIHLIEADLRNFEISKTNISQSTEQEMASLWSFDDARAKAQFEEYKRNYFEGSL

approximately 65 kDa

• 
  Greater than 95% as determined by reducing SDS-PAGE.

溶液.

Supplied as a 0.2 μm filtered solution of 50 mM Tris-HCL, 300 mM NaCL, pH 8.0.

<1 EU/μg, determined by LAL method.

N/A.

Stored at -80°C for 1 year. It is stable at -20°C for 3 months after opening. It is recommended to freeze aliquots at -80°C for extended storage. Avoid repeated freeze-thaw cycles.

Shipping with dry ice.