9012-63-9
中文名称
霍乱毒素
英文名称
CHOLERA TOXIN
CAS
9012-63-9
分子式
NULL
基本信息
中文别名
霍乱毒素霍乱菌素
英文别名
Cholergencholeragen
CHOLERA TOXIN
Choleragenoid
choleraexotoxin
exo-enterotoxin
Toxins, cholera
CHOLERA ENTEROTOXIN
VIBRIO CHOLERAE TOXIN
choleraentero-exotoxin
所属类别
生物化工：霍乱毒素B亚单位安全数据
警示词危险
危险性描述H300+H310-H332-H412
危险品标志T
危险类别码24/25-52/53
安全说明36/37-45-61
危险品运输编号3172
WGK Germany2
RTECS号LF3100000
危险等级6.1
包装类别I
毒性cholera toxin is secreted
by the gram-negative bacterium Vibrio cholerae. It is a gastrointestinal
toxin that increases adenylate cyclase activity of mucosa
of the small intestine, thereby increasing cyclic AMP within
these cells. Cyclic AMP stimulates active transport of ions by
these epithelial cells, resulting in a large efflux of Na+ and water
into the gut. The toxin enters cells by interacting with a GM1
ganglioside on the cell surface. After entry, the A1 subunit catalyzes
the transfer of an ADP-ribose unit from NAD+ to an arginine
side chain of the adenylate cyclase regulatory G protein,
blocking its GTPase activity. Thus the adenylate cyclase deactivation
mechanism is destroyed, and cyclic AMP is continually
produced. The major sign of cholera poisoning is severe diarrhea;
several liters of body water may be lost within a few hours,
leading to shock and death if fluid is not replaced. Treatment
involves physiological support (including i.v. fluids) and antibiotics.
常见问题列表
简介
霍乱毒素是由霍乱弧菌分泌的一种蛋白质复合物，是霍乱弧菌引起严重疾病所必需的。组成
霍乱毒素由（Cholera toxin,CT）两个亚单位组成，即A亚单位（CTA）和B亚单位（CTB）。A亚单位是霍乱毒素的活性部分，B亚单位的主要功能是通过与哺乳动物小肠上皮细胞上的单唾液酸神经节苷脂GM1结合而使得A亚单位进入细胞。5个CTB与1个CTA以氢键和盐桥连接在一起，形成紧凑而稳定的AB5圆筒状六聚体蛋白。霍乱毒素被认为是最有效的口服免疫原之一。口服CT不但可以使机体产生针对CT的免疫反应，而且可以增强与CT同时给予的其他抗原的免疫反应。作用机制
霍乱毒素可以增强肠粘膜的通透性，从而增加抗原的摄入量；
选择性诱导以Th2为主的免疫反应，从而增加特异性黏膜IgA抗体的产生；
可诱导IL-4和IL-5显著提高，而IL-2和IFN-gamma水平无明显变化。
生物活性
Cholera toxin (Choleragen) 是一种AB(5) 亚单位毒素，通过结合质膜上的神经节苷脂 GM1 进入宿主细胞，并通过跨高尔基体网络逆行进入内质网。Choleragen 通过催化促鸟嘌呤核苷酸结合蛋白 Gsα 的 ADP 核糖基化激活腺苷酸环化酶 (adenylate cyclase)。体外研究
In the ER, a portion of Cholera toxin, the enzymatic A1-chain, is unfolded by protein disulfide isomerase and retro-translocated to the cytosol by hijacking components of the ER associated degradation pathway for misfolded proteins.
Cholera toxin acts as an ADP-ribosyltransferase to disrupt intracellular signaling in the target cell. Cholera toxin moves by vesicle carriers from the cell surface to the endoplasmic reticulum (ER) of an intoxicated cell.