X-ray spectroscopy and X-ray diffraction at wavelengths near the K-absorption edge of phosphorus

• Published in: Journal of synchrotron radiation Vol. 12; no. 4; pp. 402 - 409
• Main Authors: Biou, Valérie, Kahn, Richard, Mas, Corinne, Bösecke, Peter, Bois, Jean-Marie, Brandolin, Gérard, Nauton, Lionel, Nury, Hugues, Pebay-Peyroula, Eva, Vicat, Jean, Stuhrmann, Heinrich
• Format: Journal Article
• Language: English
• Published: 5 Abbey Square, Chester, Cheshire CH1 2HU, England Munksgaard International Publishers 01.07.2005; International Union of Crystallography
• Subjects: ADP/ATP carrier protein; anomalous diffraction; Biochemistry; Biochemistry, Molecular Biology; Carbon-Oxygen Lyases; Carbon-Oxygen Lyases - analysis; Carbon-Oxygen Lyases - chemistry; Equipment Design; Equipment Failure Analysis; fluorescence; Halobacterium; Halobacterium - chemistry; Life Sciences; Mitochondrial ADP, ATP Translocases; Mitochondrial ADP, ATP Translocases - analysis; Mitochondrial ADP, ATP Translocases - chemistry; Molecular Conformation; Phosphorus; Phosphorus - analysis; Phosphorus - chemistry; phosphorus K-edge; Protein Conformation; Purple Membrane; Purple Membrane - chemistry; Spectrometry, X-Ray Emission; Spectrometry, X-Ray Emission - instrumentation; Spectrometry, X-Ray Emission - methods; X-Ray Diffraction; X-Ray Diffraction - instrumentation; X-Ray Diffraction - methods
• ISSN: 1600-5775; 0909-0495; 1600-5775
• DOI: 10.1107/S0909049505009222

Phosphorus is an abundant element in living organisms. It is traceable by its X‐ray absorption spectrum which shows a strong white line at its K‐edge, comparable with that observed for the LIII edges of rare earth ions. With purple membrane, the variation of the imaginary part of the anomalous dispersion of phosphorus is found to be close to 20 anomalous electron units. Anomalous diffraction experiments at wavelengths near the K‐absorption edge of phosphorus confirm this result. The spatial distribution of lipids derived from anomalous diffraction agrees with earlier results from neutron diffraction. Test experiments on single crystals of the carrier protein using 5.76 Å photons gave a first low‐resolution diffraction pattern. Various techniques of crystal mounting were attempted. In addition, fluorescence measurements on a solution of threonine synthase appear to hint at a change of the phosphate environment of the cofactor upon activator binding.