Both total proteome and differential proteins were effectively extracted, separated and selected by a combined approach of both differential centrifugation and 2D-PAGE in liver of Paralichtys olivaceus( POL) under the stress of cadmium chloride as an artificial pollution source. Approximately 800 spots for extraction of whole protein separated with 2D-PAGE were obtained by direct lysis in the POL. In addition, approximately 11 differential proteins in POL were also obtained under the stress of cadmium chloride. The differential centrifugal were used to prepare three sedimentation and a plasmolysis proteins, called POL component Ⅰ, POL component Ⅱ, POL component Ⅲ, and POL component Ⅳ(plasmolysis protein), respectively. Total protein spots for each gel were calculated to have 380, 550, 500, and 850, respectively, approximately 2280 spots in sum, while total spots are much higher than those by direct lysis approach. Using the comparison method, approximately 54 differential proteins in POL were obtained by a combined technology of both differential and two dimensional polyacylaminde gel electrophoresis(2D-PAGE) methods under the stress of cadmium chloride. In addition, these differential proteins can be further identified by peptide mass fingerprint(PMF). Here, these combined techniques can be effectively used to extract, separate and identify the whole proteins and the differential proteins including protein markers in the biological tissue.

The recombinant plasmid of mChlL-18 prokaryotic expression was transformed into E.coli BL21(DE3) strain and then induced by IPTG at 37℃.After crushed and washed,the expressing inclusion bodies were thoroughly denatured with 6 mol/L guanidine hydrochloride.Then according to experiment design,the effects of rChlL-18 protein refolding yield at different densities were investigated by the systems of artificial chapercne at different densities.Experiment results indicate that there is a optimal condition on assiting rChIL-18 protein by using the artificial chaperone technique.The optimal condition can improve the refolding yield of rChIL-18 protein,and then the expressed product of fusion chicken IL-18 gene in E.coli has a relativity high bioactivity.