TABLE 2.

Activity assay of HCoV-HKU1

SubstrateaKm (μM)kcat
C83.2 ± 13.31.1 ± 0.12
H22.3 ± 5.20.09 ± 0.013
SMC265.3 ± 21.50.03 ± 0.001
  • a Substrate C refers to the consensus substrate of CoV Mpros with the sequence MCA-AVLQSGFR-Lys(Dnp)-Lys-NH2. Substrate H refers to the specific substrate of HCoV-HKU1, including a mutation at the P1 site from glutamine to histidine, with the sequence MCA-PRLHCTTN-Lys(Dnp)-Lys-NH2. Substrate SMC refers to the consensus substrate, including a mutation at the P1 site from glutamine to histidine, with the sequence MCA-AVLHSGFR-Lys(Dnp)-Lys-NH2.