Table 1.
Kinetic parameters of the degradation of selected fluorogenic substrates by CHIKV nsP2 protease
Substrate | Junction | Km (μM) | kcat (×10−6 s−1) | kcat/Km (s−1 M−1) |
---|---|---|---|---|
Boc-AGA-MCA | nsP1/nsP2 | 2,422 | 932 | 0.38 |
Boc-AGG-MCA | nsP3/nsP4 | 232 | 374 | 1.61 |
Dabcyl-AGAGIIE-Edans | nsP1/nsP2 | ND | ND | ND |
Dabcyl-AGGYIFSE-Edans | nsP3/nsP4 | 61 | 140 | 2.3 |
Non-prime substrate sequences are indicated in bold and prime substrate sequences are shown in italics. Protease activity was assayed in Tris 50 mM pH 9.5, NaCl 10 mM using a substrate concentration ranging from 25 to 200 μM. Standard reaction contained the CHIKV nsP2pro protease at a concentration of 0.5 μM. The kinetic parameters for the degradation of Dabcyl-AGAGIIE-Edans have not been determined (ND) because of the too low activity of the protease towards this substrate.