①Measured by its binding ability in a functional ELISA. Immobilized SARS-CoV S-RBD at 2 μg/ml can bind Paguma larvata ACE2, the EC50 is 5.056-7.559 ng/ml.②Recombinant Paguma larvata ACE2 protein enzyme activity is measured by its ability to cleave fluorogenic peptide substrate-OH), The Km is 22.84 μM.