RECONSTITUTION OF THE CORE COMPLEX (ALPHA-BETA)(3)(APC)L(C)(8.9) OF THE PHYCOBILISOME FROM MASTIGOCLADUS-LAMINOSUS USING THE L(C)(8.9) LINKER POLYPEPTIDE OVEREXPRESSED IN ESCHERICHIA-COLI

The apcC gene from Mastigocladus laminosus encodes the linker polypept ide L(C)8.9 located in the phycobilisome core. AT7 RNA polymerase expr ession system was used to express the linker polypeptide L(C)8.9 from M. laminosus in Escherichia coli. The apcC gene product was expressed as an inclusion body which was solubilized in a buffer containing 8m u rea. Final purification was achieved by ion exchange chromatography on Fractogel TSK CM 650 (S). In addition, a method for preparative isola tion of the L(C)8.9 linker polypeptide from M. laminosus by reverse ph ase chromatography is presented. Both L(C)8.9 isolated from M. laminos us and overexpressed in E. coli were capable of reconstituting the com plex (alphabeta)3(APC)L(C)8.9. The reconstituted complex was identical to preparations isolated from M. laminosus in terms of polypeptide co mposition, absorption and fluorescence emission spectroscopy.