Table 3.
Kinetic Parameters of Saporin L3 Measured in 100 mM Tris (pH 7.7)
| substrate | kcat (min−1) | Km (μM) | kcat/Km (M−1 s−1) |
|---|---|---|---|
| 5,7A10 (5′-CGCGAGAGCG-3′) | 289 ± 4 | 70 ± 3 | (6.9 ± 0.4) × 104 |
| 4A10 (5′-CGCAGGGGCG-3′) | 67 ± 2 | 174 ± 10 | (6.4 ± 0.4) × 103 |
| 5A10 (5′-CGCGAGGGCG-3′) | 187 ± 25 | 421 ± 81 | (7.4 ± 1.8) × 103 |
| 6A10 (5′-CGCGGAGGCG-3′) | 392 ± 10 | 82 ± 5 | (8.0 ± 0.6) × 104 |
| 7A10 (5′-CGCGGGAGCG-3′) | – | – | (2.3 ± 0.2) × 103 |
| G(4A10) (5′-GCGAGGGCGC-3′) | 208 ± 7 | 222 ± 14 | (1.6 ± 0.1) × 104 |
| rabbit rRNA | 213 ± 12 | 0.094 ± 0.010a | (3.8 ± 0.4) × 107 |
| yeast tRNA | 467 ± 14 | 58 ± 5b | (1.3 ± 0.1) × 105 |
| luciferase mRNA | 199 ± 9 | 58 ± 5c | – |
a
The concentration of rRNA was calculated by the absorbance at 260 nm using an extinction coefficient of 5 × 10−7 cm−1 M−1.43
b
The average molecular weight of the tRNA from brewer’s yeast used from calculating Km is approximately 25 kDa.47
c
In units of nanograms per milliliter.