Biomaterial Database

Enrichment of a 50-kilodalton polypeptide in a photosystem II-phycobilisome particle from Porphyridium cruentum. 1986

B M Chereskin, and E Gantt

A 50-kDa polypeptide was obtained from photosynthetically active phycobilisome-photosystem II preparations from the red alga Porphyridium cruentum after removal of phycobiliproteins. Removal of phycobiliproteins caused destabilization of the structure of the phycobilisome-photosystem II preparations and was accompanied by a decline in photosystem II activity (oxygen-evolution and dichlorophenol-indophenol (DPIP) reduction). The treatments in increasing relative effectiveness were: addition of EDTA (10 mM), lowering the pH (6.8----4.4), and lowering the ionic strength (to ca. 1 mM phosphate). The lowering of the ionic strength by dialysis resulted in a preparation highly enriched in a 50-kDa polypeptide (apparent molecular mass on SDS-PAGE). This preparation retained photosystem II activity as evidenced by the photoreduction of DPIP in the presence of diphenylcarbazide (222 mumol DPIP/mg chlorophyll/h). Also it had a 698-nm (77K) fluorescence emission maximum, as compared to a 668-nm emission in the unfractionated preparation, which indicates enrichment of the photosystem II reaction center. Comparing our results with those obtained from green plants and a cyanobacterium leads us to suggest that the reaction center II polypeptides are highly similar in all chlorophyll alpha-containing plants.

UI	MeSH Term	Description	Entries
D009994	Osmolar Concentration	The concentration of osmotically active particles in solution expressed in terms of osmoles of solute per liter of solution. Osmolality is expressed in terms of osmoles of solute per kilogram of solvent.	Ionic Strength,Osmolality,Osmolarity,Concentration, Osmolar,Concentrations, Osmolar,Ionic Strengths,Osmolalities,Osmolar Concentrations,Osmolarities,Strength, Ionic,Strengths, Ionic
D010455	Peptides	Members of the class of compounds composed of AMINO ACIDS joined together by peptide bonds between adjacent amino acids into linear, branched or cyclical structures. OLIGOPEPTIDES are composed of approximately 2-12 amino acids. Polypeptides are composed of approximately 13 or more amino acids. PROTEINS are considered to be larger versions of peptides that can form into complex structures such as ENZYMES and RECEPTORS.	Peptide,Polypeptide,Polypeptides
D010940	Plant Proteins	Proteins found in plants (flowers, herbs, shrubs, trees, etc.). The concept does not include proteins found in vegetables for which PLANT PROTEINS, DIETARY is available.	Plant Protein,Protein, Plant,Proteins, Plant
D002413	Cations, Divalent	Positively charged atoms, radicals or groups of atoms with a valence of plus 2, which travel to the cathode or negative pole during electrolysis.	Divalent Cations
D002734	Chlorophyll	Porphyrin derivatives containing magnesium that act to convert light energy in photosynthetic organisms.	Phyllobilins,Chlorophyll 740
D004591	Electrophoresis, Polyacrylamide Gel	Electrophoresis in which a polyacrylamide gel is used as the diffusion medium.	Polyacrylamide Gel Electrophoresis,SDS-PAGE,Sodium Dodecyl Sulfate-PAGE,Gel Electrophoresis, Polyacrylamide,SDS PAGE,Sodium Dodecyl Sulfate PAGE,Sodium Dodecyl Sulfate-PAGEs
D006863	Hydrogen-Ion Concentration	The normality of a solution with respect to HYDROGEN ions; H+. It is related to acidity measurements in most cases by pH	pH,Concentration, Hydrogen-Ion,Concentrations, Hydrogen-Ion,Hydrogen Ion Concentration,Hydrogen-Ion Concentrations
D000461	Rhodophyta	Red algae whose color results from predominace of the red pigment (PHYCOERYTHRIN). However, if this pigment is destroyed, the algae can appear purple, brown, green, or yellow. Two important substances found in the cell walls of red algae are AGAR and CARRAGEENAN. Some rhodophyta are notable SEAWEED (macroalgae).	Algae, Red,Red Algae
D045322	Photosynthetic Reaction Center Complex Proteins	Protein complexes that take part in the process of PHOTOSYNTHESIS. They are located within the THYLAKOID MEMBRANES of plant CHLOROPLASTS and a variety of structures in more primitive organisms. There are two major complexes involved in the photosynthetic process called PHOTOSYSTEM I and PHOTOSYSTEM II.	Photosynthetic Complex,Photosynthetic Reaction Center,Photosynthetic Reaction Center Complex Protein,Photosynthetic Complexes,Photosynthetic Reaction Centers,Center, Photosynthetic Reaction,Complex, Photosynthetic,Complexes, Photosynthetic,Reaction Center, Photosynthetic,Reaction Centers, Photosynthetic
D045332	Photosystem II Protein Complex	A large multisubunit protein complex found in the THYLAKOID MEMBRANE. It uses light energy derived from LIGHT-HARVESTING PROTEIN COMPLEXES to catalyze the splitting of WATER into DIOXYGEN and of reducing equivalents of HYDROGEN.	Chloroplast Reaction Center Protein D1,D1 Photosystem II Protein, Plant,Light-Induced D1 Protein, Photosystem II,Oxygen Evolving Enzyme,PRCP II D2 Protein,Photosystem II,Photosystem II Reaction Center,Photosystem II Reaction Center Complex D1 Protein,Photosystem II Reaction Center Complex D2 Protein,RCII-D1 Protein,Water Oxidase,Water-Splitting Enzyme of Photosynthesis,Enzyme, Oxygen Evolving,Evolving Enzyme, Oxygen,Light Induced D1 Protein, Photosystem II,Oxidase, Water,Photosynthesis Water-Splitting Enzyme,Water Splitting Enzyme of Photosynthesis