Primary Study Of Recombinant Allophycocyanins With Optical Activity

Phycobiliproteins, important light-harvesting antenna proteins in some prokaryotic and eukaryotic algae, are made up of apoproteins and noncyclic tetrapyrrole chromophones. Since many bioactivities, such as antioxidative, antiinflammatory, antitumor, antivirus and so on, have been found from natural phycobiliproteins, it is essential to produce these proteins with stable structures and effects by gene engineering.Based on former research about recombinant allophycocyanin (rAPC) and recombinant a subunit of C-phycocyanin (optically active), the gene of a subunit of allophycocyanin, apcA, was combined with a pCDFDuet-1 vector, and two new recombinant vectors (enzymatic and self catalyzed) were constructed. The vectors could play a role in Escherichia coli to produce apolipoprotein and chromophone and connect with each other. Finally, new recombinant proteins with optical activity were produced. The recombinant strain E.coli BL21(DE3) was cultured to OD₆₀₀=23.52 in a 5L fermentor. The fermentation technique was improved to reduce the production of inclusion bodies.The recombinant proteins were purified by metal chelating affinity chromatography. Compared with the two new proteins expressed by two vectors, we found that the phycocyanin lyase E and F (CpcE/F) could influence the fluorescent spectrum of recombinant proteins, which would provide a clew to find the mechanism of phycobiliproteins' fluorescent activities.