ACE2 Protein, Human (HEK293, His, solution)

Materials
Assay buffer: 75 mM Tris, 1 M NaCl, pH 7.5
ACE2 Protein, Human (HEK293, His, solution) (HY-P7441)
Substrate: Mca-YVADAP-Lys(Dnp)-OH TFA (HY-P2616A) dissolved in DMSO to 2 mM
Standard: MCA-Pro-Leu-OH

Procedure
1. Dilute MCA-Pro-Leu-OH with assay buffer to 0, 0.0000313, 0.000313, 0.00313, 0.0313, 0.313, 3.13, 6.25, 12.5, 25, 50 μmol/L respectively. Add 100 μL of each to the wells to start the reaction. Read at excitation and emission wavelengths of 320 nm and 405 nm respectively. Plot a standard curve with the standard concentration as the abscissa and the measured RFU as the ordinate, and obtain the standard curve equation.
2. Dilute the protein to 200 μg/mL with sterile water first. Then dilute Human ACE2 to 0.2 μg/mL with assay buffer.
3. Dilute the substrate to 40 μM with assay buffer.
4. Add 0.2 μg/mL Human ACE2 to a black well plate, 50 μL per well, and add 50 μL of 40 μM substrate; for blank wells, add 50 μL assay buffer and 50 μL 40 μM substrate. Set up three replicate wells for each group.
5. Read in kinetic mode for 5 minutes at excitation and emission wavelengths of 320 nm and 405 nm respectively.
6. Calculate Specific Activity：