title: 500 MHz 1H NMR of chlorophylls in the major light-harvesting chlorophyll-protein complex of photosystem II.
abstract: 500 MHz 1H NMR spectra were obtained of solutions containing oligomeric and monomeric forms of Chl a/b-P2, the major light-harvesting chlorophyll a/b-protein complex of photosystem II, isolated from thylakoid membranes of barley (Hordeum vulgare). Oligomers showed only a broad unresolved spectrum, but for monomers several downfield-shifted chlorophyll proton resonances were observed, assigned to the alpha and beta methine protons and the formyl proton of Chl-b. Identifying the observed shifts as ring-current shifts, these NMR data can be matched with previously obtained optical data confirming the trimeric arrangement of Chl-b in Chl a/b-P2 protein, with a distance between the chromophore centers of approximately 12 A.
authors.affiliation: Department of Molecular Physics, Agricultural University, Wageningen, The Netherlands.
authors.forename: C
authors.initials: C
authors.lastname: Dijkema
authors.forename: G F
authors.initials: GF
authors.lastname: Searle
authors.forename: T J
authors.initials: TJ
authors.lastname: Schaafsma
mesh_terms: D002734:Chlorophyll; D002736:Chloroplasts / Q000032:analysis; D004591:Electrophoresis, Polyacrylamide Gel; D001467:Hordeum; D045342:Light-Harvesting Protein Complexes; D046911:Macromolecular Substances; D009682:Magnetic Resonance Spectroscopy; D045322:Photosynthetic Reaction Center Complex Proteins; D045332:Photosystem II Protein Complex; D010940:Plant Proteins
chemical_list: D045342:Light-Harvesting Protein Complexes; D046911:Macromolecular Substances; D045322:Photosynthetic Reaction Center Complex Proteins; D045332:Photosystem II Protein Complex; D010940:Plant Proteins; D002734:Chlorophyll