β Sheet Structure in Amyloid β Fibrils and Vibrational Dipolar Coupling
| Autor: | Cynthia Paul, Paul H. Axelsen |
|---|---|
| Rok vydání: | 2005 |
| Předmět: |
Amyloid beta-Peptides
Spectrophotometry Infrared Chemistry Hydrogen bond Beta sheet Infrared spectroscopy Hydrogen Bonding macromolecular substances General Chemistry Fibril Biochemistry Peptide Fragments Protein Structure Secondary Catalysis Coupling (electronics) Crystallography Dipole Colloid and Surface Chemistry Nuclear magnetic resonance Protein structure Magnetic dipole–dipole interaction |
| Zdroj: | Journal of the American Chemical Society. 127:5754-5755 |
| ISSN: | 1520-5126 0002-7863 |
| DOI: | 10.1021/ja042569w |
| Popis: | Fibrils formed by amyloid beta proteins were labeled with 13C at various positions and examined by infrared spectroscopy to detect vibrational dipolar coupling, implying close physical proximity. The results support key features of several recently proposed models for amyloid fibril structure, but they also add some important caveats. For instance, they support the conclusion that the beta structure is parallel; however, the coupling is not as strong as expected when residues are in register. This may be explained by out-of-register alignment of adjacent strands, or nonstandard parallel sheet structure that yields suboptimal alignment of labeled dipole moments. The data also point to a significant structural difference between fibrils formed by the 40-residue amyloid beta protein and fibrils formed by residues 10-35. |
| Databáze: | OpenAIRE |
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