论文部分内容阅读
在许多肠毒素中,霍乱毒素(CT)是分子构造和其活性已被较详细了解的一种。该毒素具有两种抗原性,生物活性不同肽(SA、SB),亚单位构造,简称为A5S或者A6B,而SA有A_1-SS-A_2和一处nick(缺口)。在电子显微镜照像可显示具立体型结构,接触细胞时,首先由SB结合细胞表面受体GM_1,接着嵌入细胞膜内,而且由A_1活化腺苷环化酶,CAMP异常增加。因NAD~++蛋白质(?)ADP-核糖基-蛋白质+尼克酰胺+H~+的反应使环化酶活化。已证明霍乱症特有的腹泻是由于上述的CT毒素的作用,因而可以说霍乱是由CT引起的中毒症。因此死菌霍乱疫苗预防效果不够理想,有待用抗毒免疫法进行类毒素的
Among many enterotoxins, cholera toxin (CT) is one that has a more detailed understanding of its molecular structure and activity. The toxin has two antigenicity, different bioactive peptides (SA, SB), subunit structure, referred to as A5S or A6B, while SA has A_1-SS-A_2 and a nick (nick). Electron microscopy can show a stereoscopic structure, contact with cells, first by SB binding cell surface receptors GM_1, and then embedded in the cell membrane, but also by A 1 activation of adenosine cyclase, CAMP abnormalities increased. Cyclase is activated by the reaction of ADP-ribosyl-protein + nicotinamide + H ~ + of NAD ~ ++ protein. Cholera-specific diarrhea has been shown to be due to the effects of the CT toxins described above, so it can be said that cholera is a toxicosis caused by CT. Therefore, the prevention effect of cholera vaccine killed less than ideal, to be anti-toxin immune toxoid