Table 2.

Cleavage efficiencies of EV71 and CVA16 3C proteases toward SPs or MPsa

PeptidePolyprotein junctionSequence (P10 to P6′)bCleavage efficiencyc
EV-3C (μM/min)CV-3C (μM/min)(EV-3C)rel(CV-3C)rel
SPs
    SP-1Vp2/Vp3 (EV-71)FAGLRQAVTQGFPTEL5.08 ± 1.2275.77 ± 0.40811.135
    SP-2Vp2/Vp3 (CV-A16)FAGLRQAVKQGIPTEL0.30 ± 0.0100.31 ± 0.0700.0600.061
    SP-3Vp3/Vp1 (EV-71)SDILQTGTIQGDRVADNDNDNDND
    SP-4Vp3/Vp1 (CV-A16)EDIEQTANIQGDPIADNDNDNDND
    SP-52A/2B (CV-A16)LWLDEEAMEQGVSDYI0.22 ± 0.0500.23 ± 0.0470.0440.044
    SP-62B/2C (CV-A16)ILGIPIVQKQSASWLK0.055 ± 0.00490.063 ± 0.00330.0100.013
    SP-72C/3A (CV-A16)IGNTIEALFQGPPKFR8.37 ± 1.92910.72 ± 2.2121.6482.110
    SP-83A/3B (CV-A16)VIYKLFAGFQGAYSGA0.56 ± 0.0430.63 ± 0.0070.1110.125
    SP-93B/3C (CV-A16)KPVLRTATVQGPSLDF4.10 ± 0.8394.30 ± 0.1370.8090.847
    SP-103C/3D (EV-71)LKRSYFASEQGEIQWV8.26 ± 0.1889.78 ± 0.8271.6261.925
    SP-113C/3D (CV-A16)LKRGYFASEQGEIQWM5.01 ± 0.9925.09 ± 0.8530.9871.002
MPs
    MP-1FAGLAQAVTQGFPTEL2.70 ± 0.1352.93 ± 0.1280.5300.576
    MP-2FAGLRAAVTQGFPTEL4.11 ± 0.1864.45 ± 0.3350.8090.876
    MP-3FAGLRQLVTQGFPTEL0000
    MP-4FAGLRQAVKQGFPTEL0.902 ± 0.0080.906 ± 0.0460.1780.178
    MP-5FAGLRQAVFQGFPTEL14.22 ± 1.68118.65 ± 2.4462.8003.671
    MP-6FAGLRQAVEQGFPTEL3.65 ± 0.2853.79 ± 0.2300.7120.747
    MP-7FAGLRQAVTQSFPTEL0.21 ± 0.0450.27 ± 0.0380.0410.054
  • a Synthetic 16-mer peptides (covering all the junction sites within the polyproteins of EV71 and CVA16 [SPs] or containing amino acid mutations within the P6-P1′ region of SP-1 [MPs]) were analyzed for their susceptibilities to 3C cleavage as described in Materials and Methods.

  • b The scissor bond is shown in boldface, and the mutated residues are underlined.

  • c The cleavage efficiency was defined as the average rate within 5 min of a selected peptide being cleaved by 5 μM either protease with an initial peptide concentration of 500 μM. The efficiency of EV71 3C toward the SP-1 peptide was used as the reference to calculate the relevant efficiencies. ND, not determined due to dissolving problems. The results are the averages of three independent assays.