The phycobilisomes of the cyanobacterium Arthrospira (Spirulina) maxima
Por:
Gómez-Lojero C., Pérez-Gómez B., Prado-Flores G., Krogmann D.W., Cárabez-Trejo A., Peña-Diaz A.
Publicada:
1 ene 1997
Resumen:
The phycobilisomes (PBS) of the cyanobacterium Arthrospira (Spirulina) maxima have been isolated from axenically grown cells. The largest PBS were obtained from samples of the axenic culture harvested in the stationary phase. The fluorescence emission maximum is between 670 and 680 nm. Morphologically, the PBS have an hemidiscoidal shape with a tricylindrical core, and six rods arranged radially around the core. The polypeptide composition was characterized by a combination of isoelectrofocusing, SDS-PAGE and reverse phase HPLC. Five distinct groups of polypeptides are described: (1) an 80 kDa polypeptide bearing a bilin (L(CM)) isolated by LiDS-PAGE at 4°C; (2) two polypeptides of 50 and 45 kDa present in variable amounts from preparation to preparation; (3) three polypeptides of 36, 33 and 30 kDa molecular mass, identified as rod and core-rod linker polypeptides; (4) six different chromoproteins with molecular masses around 18 kDa, identified as ?(PC), ?(PC), ?(AP) and ?(AP), ?(AP-B), and ?17. In the PBS of A. maxima, phycocyanin is the major constituent, four times more abundant than allophycocyanin; and (5) two small colorless polypeptides, of 10 and 8 kDa molecular mass. Electrofocusing was performed on the PBS components and all the subunits bearing a chromophore showed an acidic pI. All the linkers showed a basic pI except the small polypetide of L(R)10, which showed a pI of 5. We conclude that the PBS of A. maxima exhibit a hemidiscoidal form and a tricylindrical core.
Filiaciones:
Gómez-Lojero C.:
Departamento de Bioquímica, Ctro. Invest. y Estud. Avanzados IPN, Apartado Postal 14-740, 07000, México, D.F., Mexico
Pérez-Gómez B.:
Departamento de Bioquímica, Ctro. Invest. y Estud. Avanzados IPN, Apartado Postal 14-740, 07000, México, D.F., Mexico
Prado-Flores G.:
Depto. Prod. Agric. y Anim. Univ. A., 04960, México, D.F., Mexico
Krogmann D.W.:
Department of Biochemistry, Purdue University, West Lafayette, IN 47907-1153, United States
Cárabez-Trejo A.:
Depto. Biol. Cel. y Tisular F. M., México, D.F., Mexico
Peña-Diaz A.:
Departamento de Microbiologia, Inst. Fisiol. Cel. UNAM, Apartado Postal 70-243, 045100, México, D.F., Mexico
|