Reversible chemical cross-linking of the light-harvesting polypeptides of Rhodopseudomonas viridis.
The topography of the light-harvesting polypeptides of Rhodopseudomonas viridis was investigated using cleavable chemical cross-linkers. To this end a set of succinimidyl esters and surface-specific sulfosuccinimidyl esters of different span widths were synthesized. The cross-linking reagents have been characterized using NMR and infrared spectroscopy and thin-layer chromatography. The cross-linking reaction was carried out under physiological conditions and the aggregates were analyzed by the methods of one- and two-dimensional polyacrylamide gel electrophoresis and by immunoblot analysis. We found cross-linkage between B1015-alpha and B1015-alpha, between B1015-alpha and B1015-beta and B1015-beta and B1015-beta. Aggregates of higher molecular mass were hetero-oligomers of B1015-alpha and B1015-beta containing three and four polypeptides, respectively. The results obtained in this work indicate a very tight contact among the light-harvesting polypeptides. We assume that the light-harvesting polypeptides are localized alternately as dimers of B1015-alpha and B1015-beta around the reaction centre core.
F R
FR
Ludwig
F A
FA
Jay
D001426:Bacterial Proteins / Q000032:analysis*; D003432:Cross-Linking Reagents / Q000138:chemical synthesis; D004591:Electrophoresis, Polyacrylamide Gel; D007120:Immunochemistry; D008565:Membrane Proteins / Q000032:analysis; D010455:Peptides / Q000032:analysis*; D045322:Photosynthetic Reaction Center Complex Proteins; D012241:Rhodopseudomonas / Q000032:analysis*; D012834:Silver; D013194:Staining and Labeling; D013388:Succinimides / Q000138:chemical synthesis
D001426:Bacterial Proteins; D003432:Cross-Linking Reagents; D008565:Membrane Proteins; D010455:Peptides; D045322:Photosynthetic Reaction Center Complex Proteins; D013388:Succinimides; D012834:Silver