Recombinant expression and functional characterization of a Serpin-type serine proteinase inhibitor(Fc-serpin) from the Chinese shrimp(Fenneropenaeus chinensis)

Serine proteinase inhibitors( SPI) play an important role in regulating humoral immunity by controlling the activity of serine proteinase( SP) in the process of protease cascade. Serpin family members participate in numerous biological processes by regulating the activity of serine and cysteine proteinases,such as blood clotting,complement activation,fibrinolysis function,inflammation,tumor suppressor and hormone transfer process. In our previous research,w e cloned a serpin-type serine proteinase inhibitior gene from hemocytes of Chinese shrimp( Fc-serpin,GenBank accession number: DQ318857). The transcript of Fcserpin w as induced in response to the infection of bacteria and w hite spot syndrome virus( WSSV). In this research,recombinant Fc-serpin( rFc-serpin) w as successfully expressed in bacteria E. coli and purified for further research of bioactivity. The concentration of purified target proteins w as 0. 3 g / L. rFc-serpin show ed in vitro antimicrobial activity against main pathogens including Gram-positive,Gram-negative bacteria and fungi. The results suggest that rFc-serpin might play a crucial role in the innate immunity of the shrimp and is expected to be applied in disease control.