Protein-chromophore interactions in α-crustacyanin, the major blue carotenoprotein from the carapace of the lobster, Homarus gammarus a study by 13 C magic angle spinning NMR
| Autor: | George Britton, R. J. Weesie, H. J. M. de Groot, F. J. H. M. Jansen, D Askin, Johan Lugtenburg |
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| Rok vydání: | 1995 |
| Předmět: |
Magnetic Resonance Spectroscopy
Protein Conformation Biophysics Analytical chemistry Xanthophylls Biochemistry chemistry.chemical_compound Protein structure Solid-state MAS 13C NMR spectroscopy Homarus gammarus Structural Biology Astaxanthin Bathochromic shift Genetics Magic angle spinning Animals Molecular Biology biology Chemistry Proteins Carotenoprotein complex Crustacyanin Pigments Biological Cell Biology Nuclear magnetic resonance spectroscopy Chromophore Carbon-13 NMR beta Carotene biology.organism_classification Carotenoids Nephropidae Crystallography Carrier Proteins Protein-chromophore interaction |
| Zdroj: | FEBS Letters. 362:34-38 |
| ISSN: | 0014-5793 |
| Popis: | MAS (magic angle spinning) 13C NMR has been used to study protein-chromophore interactions in alpha-crustacyanin, the blue astaxanthin-binding carotenoprotein of the lobster, Homarus gammarus, reconstituted with astaxanthins labelled with 13C at the 14,14' or 15,15' positions. Two signals are seen for alpha-crustacyanin containing [14,14'-13C2]astaxanthin, shifted 6.9 and 4.0 ppm downfield from the 134.1 ppm signal of uncomplexed astaxanthin in the solid state. With alpha-crustacyanin containing [15,15'-13C2]astaxanthin, one essentially unshifted broad signal is seen. Hence binding to the protein causes a decrease in electronic charge density, providing the first experimental evidence that a charge redistribution mechanism contributes to the bathochromic shift of the astaxanthin in alpha-crustacyanin, in agreement with inferences based on resonance Raman data [Salares, et al. (1979) Biochim. Biophys. Acta 576, 176-191]. The splitting of the 14 and 14' signals provides evidence for asymmetric binding of each astaxanthin molecule by the protein. |
| Databáze: | OpenAIRE |
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