ABSTRACT
A method is described which allows the selective release and removal of the Bchla-B800 molecules from the LH2 complex of Rhodopseudomonas acidophila 10050. This procedure also allows reconstitution of approximately 80% of the empty binding sites with native Bchla. As shown by circular dichroism spectroscopy, the overall structures of the B850-only and reconstituted complexes are not affected by the pigment-exchange procedure. The pigments reconstituted into the B800 sites can also efficiently transfer excitation energy to the Bchla-B850 molecules.
Subject(s)
Bacterial Proteins , Bacteriochlorophylls/chemistry , Bacteriochlorophylls/metabolism , Light-Harvesting Protein Complexes , Photosynthetic Reaction Center Complex Proteins/chemistry , Photosynthetic Reaction Center Complex Proteins/metabolism , Photosystem II Protein Complex , Rhodopseudomonas/chemistry , Rhodopseudomonas/metabolism , Binding Sites , Buffers , Circular Dichroism , Detergents , Energy Transfer , Glucosides , Intracellular Membranes/chemistry , Intracellular Membranes/metabolism , Photosynthetic Reaction Center Complex Proteins/isolation & purification , Temperature , Time FactorsABSTRACT
A method is described for reversibly removing bacteriochlorophyll from the B800-site of the B850-850 antenna complex from Rhodobacter sphaeroides. This method uses the oligosaccharidic detergent Triton BG-10, together with an incubation at pH 5.0. Reconstitution at the B800-site has been successfully achieved for a range of modified bacteriochlorophylls. Copyright 1998 Elsevier Science B.V. All rights reserved.
