Rates of cleavage of a SNAP-25 substrate by BoNT/E preparations: nicking together with reduction potentiate the protease activity
Sample | Dithiothreitola | Initial Rate of Substrate Proteolysisb |
|---|---|---|
| nmol / min / nmol ± S.D. | ||
| Natural nicked BoNT/E | None | 53.3 ± 10.9 (n = 4) |
| 4 mM | 409 ± 125 (n = 7) | |
| 10 mM | 73.3 ± 9.4 (n = 3) | |
| DC BoNT/E | None | 82.1 ± 19.1 (n = 5) |
| 4 mM | 427 ± 81 (n = 7) | |
| 10 mM | 139 ± 9 (n = 3) | |
| SC BoNT/E | None | 93.9 ± 14 (n = 5) |
| 4 mM | 115 ± 11 (n = 6) | |
|
| 10 mM | 71.1 ± 8.1 (n = 3) |
↵ a Toxins were prereduced as described under Materials and Methods.
↵ b Initial rates of proteolysis of 15 μM GST-SNAP-25C 65 at 37°C were measured using a reverse-phase high-performance liquid chromatography method. n, number of separate individual experiments. A single batch of each toxin was used.