Abstract:
The pCOLADuet-cpcE/Fplasmid,which expressed the phycocyaninlyase encoded by cpcE/Fin Anabaena sp.PCC7120,and other plasmids,including pACYCDuet-pebA,pCDFD uet-hol-pebB,pETD uet-pecAor pETD uet-cpcA,were transformed together in E.coli BL21(DE3).After being induced by IPTG,the chromoproteins PEB-CpcA and PEB-PecA were successfully expressed in E.coli.The Absorption and fluorescence spectra showed that CpcE/Fcould catalyse the covalent attachment of PEBat Cys-84 of α-subunit of phycocyanin and phycoerythrocyanin to form the chromoprotein PEB-PecAand PEB-CpcA,respectively.Themaximal Absorption of PEB-PecA and PEB-CpcA was 555 nm,and the maximal fluorescence was 570 nm.SDS-PAGE analysis displayed the Zn2+-induced fluorescence of the bound chromophore under irradiation by 280 nm,which showed that PEB-PecA and PEB-CpcA were got with the chromophorylation in E.coli.The results showed that the lyase CpcE/F could catalyse the covalent attachment of PEB to CpcAand PecA.