9012-63-9
中文名稱
霍亂毒素
英文名稱
CHOLERA TOXIN
CAS
9012-63-9
分子式
NULL
基本信息
中文別名
霍亂毒素霍亂菌素
英文別名
Cholergencholeragen
CHOLERA TOXIN
Choleragenoid
choleraexotoxin
exo-enterotoxin
Toxins, cholera
CHOLERA ENTEROTOXIN
VIBRIO CHOLERAE TOXIN
choleraentero-exotoxin
所屬類別
生物化工：霍亂毒素B亞單位安全數(shù)據(jù)
警示詞危險(xiǎn)
危險(xiǎn)性描述H300+H310-H332-H412
危險(xiǎn)品標(biāo)志T
危險(xiǎn)類別碼24/25-52/53
安全說(shuō)明36/37-45-61
危險(xiǎn)品運(yùn)輸編號(hào)3172
WGK Germany2
RTECS號(hào)LF3100000
危險(xiǎn)等級(jí)6.1
包裝類別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.
常見問(wèn)題列表
簡(jiǎn)介
霍亂毒素是由霍亂弧菌分泌的一種蛋白質(zhì)復(fù)合物，是霍亂弧菌引起嚴(yán)重疾病所必需的。組成
霍亂毒素由（Cholera toxin,CT）兩個(gè)亞單位組成，即A亞單位（CTA）和B亞單位（CTB）。A亞單位是霍亂毒素的活性部分，B亞單位的主要功能是通過(guò)與哺乳動(dòng)物小腸上皮細(xì)胞上的單唾液酸神經(jīng)節(jié)苷脂GM1結(jié)合而使得A亞單位進(jìn)入細(xì)胞。5個(gè)CTB與1個(gè)CTA以氫鍵和鹽橋連接在一起，形成緊湊而穩(wěn)定的AB5圓筒狀六聚體蛋白?；魜y毒素被認(rèn)為是最有效的口服免疫原之一?？诜﨏T不但可以使機(jī)體產(chǎn)生針對(duì)CT的免疫反應(yīng)，而且可以增強(qiáng)與CT同時(shí)給予的其他抗原的免疫反應(yīng)。作用機(jī)制
霍亂毒素可以增強(qiáng)腸粘膜的通透性，從而增加抗原的攝入量；
選擇性誘導(dǎo)以Th2為主的免疫反應(yīng)，從而增加特異性黏膜IgA抗體的產(chǎn)生；
可誘導(dǎo)IL-4和IL-5顯著提高，而IL-2和IFN-gamma水平無(wú)明顯變化。
生物活性
Cholera toxin (Choleragen) 是一種AB(5) 亞單位毒素，通過(guò)結(jié)合質(zhì)膜上的神經(jīng)節(jié)苷脂 GM1 進(jìn)入宿主細(xì)胞，并通過(guò)跨高爾基體網(wǎng)絡(luò)逆行進(jìn)入內(nèi)質(zhì)網(wǎng)。Choleragen 通過(guò)催化促鳥嘌呤核苷酸結(jié)合蛋白 Gsα 的 ADP 核糖基化激活腺苷酸環(huán)化酶 (adenylate cyclase)。體外研究
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.