Objective : construct high - level expression system of echistatin in e . coli methods : obtain amino - acid sequence of echistatin from genebank database . considering the bias of usage of 61 available aminoacid codons in e . coli , design the coding sequence of echistatin , synthesize the dna sequence chemically , get single copy coding gene and repeated two copy coding gene of echistatin . insert the sequence into expression vector pbv220 , and more , we construct fusion expression clone of echistatin with pcr , identify the recombinant vector by dna sequencing 目的构建蛇毒锯鳞蝰素( echistatin )的原核高效表达体系方法由genebank数据库检索蛇毒锯鳞蝰素( echistatin )的氨基酸序列，结合大肠杆菌蛋白质合成体系对氨基酸密码子使用的偏爱性，设计了echistatin编码基因，体外人工合成编码基因dna片段，通过适当的限制性内切酶位点插入表达载体pbv220 ，分别构建了echistatin的单拷贝表达克隆、双拷贝串联表达克隆；进一步通过pcr技术构建echistatin的融合表达基因克隆。
