Table 2. Specificity of rhinocerase towards various fluorescent substrates.
| Activity (Substrate) | Enzyme | Km a (µM) | Vmax a(s−1) | Kcat a (s−1) | Kcat/Km x 103a (µM−1s−1) |
| Fibrinolytic activity (Ala-Leu-Lys – AMC) | Venom | 12.26±0.56 | 0.32±0.05 | - | - |
| Rhinocerase | 20.29±0.6 | - | 60.84±0.23 | 3001.29±99.57 | |
| Kininogenolytic activity (Ala-Leu-Arg – AMC) | Venom | 14.3±0.33 | 0.38±0.02 | - | - |
| Rhinocerase | 32.19±0.12 | - | 104.28±4.77 | 3239.8±146.28 | |
| Plasminogenolytic activity (Gly-Gly-Arg – AMC) | Venom | 39.89±1.15 | 0.37±0.02 | - | - |
| Rhinocerase | No activity was detected | ||||
a
The values are mean ± S.D. (n = 3).
100 µg of rhinocerase were incubated with different concentrations of various fluorescent substrates at 37°C for 7 minutes. The amount of AMC released was measured at an excitation wavelength of 366 nm and an emission wavelength of 460 nm at time intervals up to 7 minutes. 100 µg of B. g. rhinoceros venom were also used at the same experimental conditions for comparison. Kinetic parameters were determined from Lineweaver-Burk plots.