TABLE 3.
Effect of N-terminal acetylation on biophysical properties of αS
| Probed parameter | Technique used | Effect of N-terminal acetylation | |
|---|---|---|---|
| Primary structure | Subcellular localization/distribution | Fluorescence microscopy | No significant effect (17. 20) |
| Primary native structure | Mass spectrometry, SDS-PAGE, Native-PAGE, CD spectroscopy | Monomeric (15, 18, 20 and this paper) Tetrameric (16. 72) |
|
| Secondary structure | Membrane binding of αS monomer | CD spectroscopy, Isothermal calorimetry, nuclear magnetic resonance | Enhanced binding to GM1 gangliosides (41) Comparable binding to GM3, POPS lipids (18, 31, 41) |
| Aggregation properties | Amyloid formation rate | Thioflavin T fluorescence | Two-fold decrease (19. 73) |
| No significant effect (18. 20) | |||
| Aggregation lag-time variability | Thioflavin T fluorescence | Decreases (19 and this paper) | |
| Fibrillar structure | Fibril height(nm) | Atomic force microscopy | No significant effect (this paper) |
| Secondary structure | CD spectroscopy of fibrils | Increased β-sheet content (45 and this paper) | |
| High resolution Secondary structure | 2D-IR spectroscopy | Increased fibril homogeneity (this paper) | |
| Solvent exposure of fibril core | Fluorescence spectroscopy | No significant effect (this paper) | |
| Urea digestion assay | Thioflavin T fluorescence | No significant effect (this paper) | |
| Proteinase-K digestion assay | Thioflavin T fluorescence and SDS-PAGE | No significant effect (this paper) | |
| Mass mapping | Scanning Transmission Electron Microscopy (STEM) | - 2 monomers per nm (71) - 2–3 monomers per nm of fibril (this paper) |