title: The biogenesis of the cyanellae of Cyanophora paradoxa. I. Polypeptide composition of the cyanellae.
abstract: Based on polypeptide separation, protein purification and immunoblotting techniques using heterologous antibodies, we have been able to identify several photosynthetically important polypeptide components of the cyanellae of Cyanophora paradoxa. Cytochrome c-552 and ferredoxin have been purified to electrophoretic homogeneity and exhibit apparent molecular masses of 10.5 and 9.0 kDa, respectively. Cytochrome c-552 has an isoelectric point of pH 4.2 +/- 0.1. Plastocyanin was immunologically and spectrally undetectable even in cells grown in the presence of Cu2+. Polypeptides for cytochromes f, b-6 and c-552 have been located in electrophoretically resolved thylakoid samples by using the TMBZ-staining procedure. Intact phycobilisomes have been purified and characterized with respect to polypeptide composition and absorption and emission spectra. Photosystems I and II have been isolated and characterized with respect to their photochemical activities, spectral characteristics and polypeptide composition. Photochemically active PS I complexes fluoresce maximally at 720 nm at 77 K and comprise five polypeptide subunits resolved under denaturing conditions with apparent molecular masses of 66, 21, 18, 14 and 11 kDa. PS II core complexes mediate light-dependent 3-(3,4-dichlorophenyl)-1,1-dimethylurea (DCMU)-sensitive electron transfer between 1,5-diphenylcarbazide (DPC) and 2,6-dichlorophenolindophenol (DPIP) at rates of 140-200 mumol h-1 mg-1 chlorophyll. These complexes exhibit absorption maxima at 436 and 673 nm and show fluorescence emission maxima at 685 and 695 nm at 77 K. Rubisco was separated by two-dimensional electrophoresis and immunologically characterized.
authors.affiliation: Department of Biological Sciences, University of California, Santa Barbara 93106.
authors.forename: R L
authors.initials: RL
authors.lastname: Burnap
authors.forename: R K
authors.initials: RK
authors.lastname: Trench
mesh_terms: D002458:Cell Fractionation; D002734:Chlorophyll / Q000302:isolation & purification; D003574:Cytochrome c Group / Q000302:isolation & purification; D004579:Electron Transport; D004591:Electrophoresis, Polyacrylamide Gel; D056890:Eukaryota / Q000648:ultrastructure; D015151:Immunoblotting; D045342:Light-Harvesting Protein Complexes; D008970:Molecular Weight; D015388:Organelles / Q000378:metabolism / Q000648:ultrastructure*; D010452:Peptide Biosynthesis; D010455:Peptides / Q000302:isolation & purification*; D045322:Photosynthetic Reaction Center Complex Proteins; D045524:Phycobilisomes; D010860:Pigments, Biological / Q000302:isolation & purification; D010940:Plant Proteins / Q000302:isolation & purification
chemical_list: D003574:Cytochrome c Group; D045342:Light-Harvesting Protein Complexes; D010455:Peptides; D045322:Photosynthetic Reaction Center Complex Proteins; D045524:Phycobilisomes; D010860:Pigments, Biological; D010940:Plant Proteins; C083951:cytochrome c553; D002734:Chlorophyll; C022302:cytochrome C-552