凝集素和毒素  

Lectins and Toxins

作　　者：王克夷[1] 许强[1] 

机构地区：[1]中国科学院上海生物化学研究所,上海200031

出　　处：《生物化学与生物物理学报》2000年第3期201-205,共5页

基　　金：国家自然科学基金会资助 !No .3 95 70 174&&

摘　　要：总的说来 ,凝集素并不很毒 ,但是在凝集素和毒素之间却存在一些关系。BEA类毒素可以分为两个主要部分。其中一个部分呈现糖结合活性 ,负责靶向。另一部分则具有不同的酶活性 ,决定了其毒性。从天花粉中分离得到的凝集素分享了BEA类毒素 (例如蓖麻毒素 )的一些特性。还有一些毒素可以在细胞膜上造成孔 ,形成离子通道。半夏凝集素似乎可归属于这类毒素。从蛇毒中分离得到了一些凝集素 ,它们和蛇毒中的其它一些成员在氨基酸序列上有同源性 ;同时 ,蛇毒中众所周知的毒素磷脂酶A2 的受体也含有凝集素类似的结构域。竹叶青蛇毒中存在一个C类动物凝集素。总之 。Although lectins, in general, are not very toxic, there are some relationships between lectins and toxins. BEA type toxins can be divided into two main parts. One shows sugar binding activity responsible for targeting. Another part, which possesses different enzymatic activity, determines the toxicity. The lectins isolated from Trichosanthes kirilowii share some properties with BEA type toxin, e.g. ricin. Some toxins can perforate cell membrane, forming an ion channel. A lectin from Pinellia turnata may belong to this kind of toxin. Several lectins were isolated from snake venom, sharing homologous amino acid sequences with other components in venom, while a receptor of well known toxin in venom, phospholipase A 2, contains lectin like domain. In the venom of Trimeresurus stejnegeri exists a C type animal lectin. The conclusion is that both lectins and toxins may be involved in the defense mechanism of organisms.

关 键 词：凝集素 毒素 糖结合活性 酶活性 蛋白质 

分 类 号：Q946[生物学—植物学]