Table 1.
Rate of nucleation and propagation of amyloid fibrils of WT- and ALS-variant apo-SOD1 as a function of lysine acetylation, Ac(N)
| SOD1a | Ac (∼N)b | 0 mM NaCl (n = 18) |
100 mM NaCl (n = 18) |
||||
|---|---|---|---|---|---|---|---|
| Lag time (h) (ΔLag time)c | 1/k (h)c (Δ1/k)d | P-valuee | Lag time (h) (ΔLag time)d | 1/k (h)b (Δ1/k)d | P-valuee | ||
| WT | 0 | 13.9 ± 1.1 | 1.1 ± 0.1 | 15.4 ± 1.1 | 1.8 ± 0.1 | ||
| 1 | 15.0 ± 1.2 (1.1 ± 1.6) | 2.2 ± 0.2 (1.1 ± 0.2) | 0.48 | 17.6 ± 1.6 (2.2 ± 1.9) | 2.7 ± 0.2 (0.9 ± 0.2) | 0.27 | |
| 3 | 16.5 ± 0.7 (2.6 ± 1.3) | 2.6 ± 0.1 (1.5 ± 0.1) | 0.06 | 16.9 ± 0.8 (1.5 ± 1.4) | 2.4 ± 0.1 (0.6 ± 0.1) | 0.28 | |
| 6 | 24.9 ± 1.3 (11.0 ± 1.7) | 3.3 ± 0.3 (2.2 ± 0.3) | <0.0001 | 25.5 ± 0.9 (10.1 ± 1.4) | 3.2 ± 0.3 (1.4 ± 0.3) | <0.0001 | |
| D90A | 0 | 11.9 ± 1.0 | 2.1 ± 0.2 | 9.3 ± 0.9 | 1.5 ± 0.2 | ||
| 2 | 11.1 ± 1.1 (−0.8 ± 2.1) | 3.3 ± 0.3 (1.2 ± 0.5) | 0.57 | 14.0 ± 1.1 (4.7 ± 1.4) | 2.1 ± 0.2 (0.6 ± 0.2) | 0.002 | |
| 3 | 9.8 ± 1.1 (−2.1 ± 2.1) | 3.4 ± 0.2 (1.3 ± 0.4) | 0.15 | 14.1 ± 1.1 (4.8 ± 1.4) | 2.2 ± 0.2 (0.7 ± 0.2) | 0.002 | |
| 5 | 12.4 ± 1.2 (0.5 ± 1.6) | 3.8 ± 0.2 (1.7 ± 0.2) | 0.76 | 15.2 ± 1.4 (5.9 ± 1.7) | 2.6 ± 0.2 (1.1 ± 0.2) | 0.001 | |
| A4V | 0 | 13.8 ± 1.7 | 2.2 ± 0.2 | 12.7 ± 1.3 | 2.2 ± 0.3 | ||
| 3 | 20.1 ± 2.1 (6.3 ± 2.7) | 4.1 ± 0.4 (1.9 ± 0.4) | 0.02 | 17.5 ± 1.3 (4.8 ± 1.3) | 4.8 ± 0.3 (2.6 ± 0.3) | 0.01 | |
| 4 | 11.5 ± 0.7 (−2.3 ± 1.8) | 3.2 ± 0.3 (1.0 ± 0.4) | 0.21 | 15.6 ± 2.2 (2.9 ± 2.5) | 4.6 ± 0.5 (2.4 ± 0.6) | 0.26 | |
| 9 | 28.3 ± 1.7 (14.5 ± 1.7) | 4.9 ± 0.3 (2.7 ± 0.4) | <0.0001 | 17.1 ± 1.2 (4.4 ± 1.3) | 4.7 ± 0.4 (2.5 ± 0.5) | 0.02 | |
All acetylated and unacetylated SOD1 proteins were in the metal free state with <0.06 ± 0.02 Zn2+ and < 0.03 ± 0.01 Cu2+ bound per SOD1 dimer.
Mean number of acetylated residues, per apo-SOD1 monomer, as inferred from CE and MS.
Rate of propagation expressed as inverse propagation constant (1/k).
ΔLag time and Δpropagation values are expressed relative to Ac(0) for each protein. All values and errors are listed as mean ± SE from 18 replicate ThT assays for each sample; the R2 values of all fits were >0.98.
This table only lists p-values comparing the lag time of acetylated proteins with unacetylated protein; all p-values comparing 1/k values of acetylated vs. unacetylated protein were ∼p < 0.005.