多角体polh部分片段融合EGFP的溶解性研究

Because the Polyhedrin can overexpress (high expression level),and easily dissolves in alkali condition, it always express together with foreign genes which are difficult to express. At the same time , fused protein can be easily purified by pH gradient washing and differential centrifugation. But when it was digested by the specific proteases in alkali condition, the efficiency of fused protein digested is very poor and it is difficult to collect lots of pure foreign protein. Basing on the expected tertiary structure of Polyhedrin, we chooses polyhedrin gene fragments in three different lengths, and then expresses together with report gene enhanced green fluorescent protein(EGFP) in Escherichia coli. By call-backing the pH of the fused protein expressed，it can dissolve in neutral solution(pH7.6). Lots of pure foreign protein can be collected by specific protease(thrombin) and the efficiency is high. We demonstrates that these fragments can be used to purify the expression of foreign protein and aslo provide a good foundattion for purifying lots of foreign protein.